Full-Stack Software-Developer/-Architect, mainly backend, Interims-CTO, Tech-Consulting
Aktualisiert am 10.09.2024
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 10.09.2024
Verfügbar zu: 100%
davon vor Ort: 100%
Go
PHP
Solidity
Postgres
Python
Machine Learning
TypeScript
NodeJS
Symfony
Sylius
MySQL
NestJS
SmartContracts
Softwarearchitektur
CI/CD
Kubernetes
Docker
Qdrant
Vector databases
Embeddings
vLLM
C++
C#
German
Muttersprache
English
Verhandlungssicher

Einsatzorte

Einsatzorte

Berlin (+100km) Munich (+50km)
Deutschland, Österreich
möglich

Projekte

Projekte

11 months
2024-01 - now

NLP + Machine Learning + Backend + Big Data at AI Startup

Fullstack Engineer + Architect Python Qdrant PostgreSQL ...
Fullstack Engineer + Architect

Lead Engineer & Architect | Backend, Frontend, and ML Team Leader

As the first engineer and architect on this project, I have been instrumental in shaping the system from the ground up. My role spans across backend development, leading a multi-functional team (backend, frontend, ML), and overseeing the architecture of microservices-based systems.

Our technology stack includes Python and NestJS for backend services, while the frontends leverage the Quasar Framework and NextJS. We also manage on-premise GPUs to securely host large language models (LLMs), ensuring data protection for our users.

We run Postgres and Qdrant databases with > 1 TB of data.

I bring a deep expertise in full-stack development, system architecture, and team leadership, with a focus on scalability, security, and innovative AI-driven solutions.

Python Qdrant PostgreSQL Node.js TypeScript NestJS NextJS Quasar Framework vLLM CUDA GPU
infobud GmbH
Berlin
2 years 4 months
2021-07 - 2023-10

Software Suite for Tokenization of Digital Assets

Lead Software Developer Go Solidity Node.js ...
Lead Software Developer

For the clients of [Company name on request] from the financial market, we are developing a product suite with a team of software developers, UX specialists, and lawyers, which allows issuers to emit and manage digital assets at the blockchain level. This includes:

  • Asset Management
  • Investor Management
  • Investor Dashboard
  • Fully automated handling of tokenization (Minting, Transfer, Burn)
  • Registry extracts
  • Payment options including Stripe, PayPal and cryptocurrencies
  • Invoice-Management
  • Automated dividend and interest payouts
  • Cryptocurrency processing
  • Minting Studio for issuing and distributing tokens

  • Software Architecture
  • Leading the Engineering team incl. DevOps
  • Backend Development
  • Development of On-Chain components (SmartContracts, dApps-Connectivity, RPC-APIs)

Go Solidity Node.js PHP Sylius Symfony NestJS Ethereum Ethers IPFS Web3 SmartContracts Stripe PayPal MySQL PostgreSQL Docker Kubernetes RabbitMQ Prometheus Grafana Graylog
tokenforge GmbH
Berlin
3 years 10 months
2020-01 - 2023-10

eMoney Payment Gateway API, weeCommerce AG

Lead Software Developer Go nats.io ProtoBuf ...
Lead Software Developer

As a joint project with our client weeCommerce AG, we created a Payment Gateway that can handle the complete payment processing within the framework of a WhiteLabel Banking System. The following features are provided within a REST API:


Features:
? Account opening for both private and business customers (Europe-wide)
? KYC (Know Your Customer)
? UBO (Ultimate Beneficiary Owner Check)
? Deposits of credit into internal eMoney-based wallets
? Withdrawals of credit to bank accounts via IBAN
? Transactions between wallets
? Bulk transactions between different wallets as individual transactions
? Credit Card Payments including 3DSecure


My tasks and responsibilities:

? Team Building
? Development of the entire software architecture and the final technology stack
? Technical Product Owner
? Development of the banking engine and the REST-API in Go
? Team coordination in collaboration with other developers
? Planning and coordination of peripherals (dashboards, monitoring, recovery)


Technology:

Go (Backend, Services, REST-API), nats.io (message bus), ProtoBuf (data layer / protocol),
PostgreSQL, Prometheus, Grafana, GrayLog / ElasticSearch, Traeffik, KeyCloak, Kubernetes, ReactJS for Admin-Dashboard
Go nats.io ProtoBuf Kubernetes PostgreSQL Prometheus Grafana Graylog Traeffik KeyCloak ReactJS CSPO
Berlin
4 months
2023-06 - 2023-09

Avalanche SubNet for a custom EVM-blockchain

Lead Software Developer Avalanche Go EVM ...
Lead Software Developer

Problem: 

Facing difficulties acquiring test-tokens due to drained faucets on various blockchains such

as Goerli and Polygon, my team and I frequently encountered obstacles during product testing, development, and demonstration. To circumvent these challenges, we decided to create our own EVM blockchain using Avalanche SubNets, providing us with robust Testnets to experiment with the deployment of SmartContracts, token interactions, and the minting of various token types, such as NFTs, SecurityTokens, and ReFi components.


Solution: 

Now we proudly manage our own chains, run our own faucet, operate our own block explorer via Blockscout, and, with immense gratitude to the open-source community, we even have our own SmartContract execution tool, which delivers a user experience surpassing that offered by Etherscan and its counterparts. 


Technology:

Avalanche, Go, EVM, SubNet, Blockscout, Kubernetes, DevOps


More information can be found here:
? Article on LinkedIn: [Title and URL on request]
Avalanche Go EVM SubNet Blockscout Kubernetes DevOps
Berlin
9 months
2023-01 - 2023-09

SmartContracts + d'App for Security Tokens (eWpG)

Lead Software Developer Solidity Blockchain Ethereum ...
Lead Software Developer

For [Company name on request] and its client, Chartered Investment AG & eSec, a registrar for Security Tokens, I wrote Smart Contracts and a corresponding d'App for the management and issuance of Security Tokens on the Avalanche Blockchain in accordance with the German Electronic Securities Act ("eWpG").


  • Development of the Smart Contracts in Solidity (ERC20 + ERC1155 for Permissions according to eWpG) 
  • Development of the d'App for the issuance of shares
  • Development of the d'App for the registry law
  • Development of the snapshots for the registry excerpt


Avalanche, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS


  • Announcement on Twitter  [URL on request]
  • BaFin - official record  (https://www.bafin.de/DE/PublikationenDaten/Datenbanken/Kryptowertpapiere/kryptowertpapiere_artikel.html)
  • Press Release  (https://chartered-investment.com/en/media/news/chartered-investment-und-smart-wealth-lancieren-ersten-tokenisierten-index-tracker-unter-ewpg/)
  • Contract Address  [URL on request]
Solidity Blockchain Ethereum Avalanche Polygon VueJS dApp SmartContracts ERC-20 ERC-1155 HardHat OpenZeppelin eWpG GeSAct IPFS
Berlin
2 years 3 months
2021-07 - 2023-09

Tokenization Platform for Real-World Assets (RWA)

Lead Software Developer Go Node.js TypeScript ...
Lead Software Developer

[Company name on request] is a Berlin-based technology provider that offers its customers a software toolkit for asset tokenization, that offers the possibility to tokenize assets compliant with the law, fully digital and with no code.


For [Company name on request] and its clients, we developed an All-in-one toolkit for Security Token Issuance:


The Security Token Suite enables fast, legally compliant and secure issuance of bonds and digital

securities:


? MiFiD II compliant underwriting process
? Fully automated token- and wallet generation
? Admin dashboard for efficient data- and issuance management

? eCommerce-like experience for investors

? Integration of KYC/AML, UBO and payment providers

? Stable and reliable token-minting experience

? Fully automated and scalable token issuance + transferability

? Automated token distribution

? API First Approach (Launchpad-API | Chain-API)

? Wallets as a Service (our own custody provider)

? Integration of external Custody-Providers


My tasks in detail:

? Software Architecture (Microservices)

? Team-Lead Engineering at the beginning, followed by a typical CTO-Role

? Software Development on all levels

? Cryptography

? On-Chain-/Web3 development

? Backend engineering

? Setup Infrastructure with DevOps


Technology:

Go, NodeJS, TypeScript, NestJS, PostgreSQL, SmartContracts, Solidity, PHP, Ethereum, Avalanche, Polygon, AWS KMS, Cryptography, Kubernetes, RabbitMQ, Redis, Prometheus, Graylog, Grafana, ERC-20, ERC-1155, ERC-721, BIP-32, BIP-44

Go Node.js TypeScript NestJS PostgreSQL SmartContracts Solidity PHP Ethereum Avalanche Polygon AWS KMS JCE Kubernetes Prometheus Graylog Grafana RabbitMQ Redis ERC-20 ERC-1155 ERC-721 BIP-32 BIP-44
Berlin
1 month
2022-12 - 2022-12

Technical Due Diligence - Cryptography & Blockchain

Consultant TechDD Cryptography Blockchain ...
Consultant
As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of Cryptography and Blockchain during a technical due diligence of a crypto-related company. 


My particular activities included:

? Code Reviews / Auditing
? Interviews with the CTO
? Developer interviews
? Architecture assessment
TechDD Cryptography Blockchain Distributed Ledger Distributed FileSystem StorJ
Philipps & Byrne GmbH
Berlin
1 year 6 months
2021-07 - 2022-12

SmartContracts for various NFT-projects

Lead Software Developer SmartContracts Solidity ERC-20 ...
Lead Software Developer

For [Company name on request] and its clients, I continually developed Smart Contracts for various approaches revolving around NFT and utility tokens with full test-overage. In addition, I developed a centralized backend to make the management of on-chain processes accessible via a REST API (keyword ?Web 2.5?).


My tasks in detail:
? Smart Contracts in Solidity based on:
? ERC-20
? ERC-721
? ERC-1155
? Tools for minting tokens
? Tools for managing metadata and files on IPFS

? Image processing/manipulation for generative Art using Puppeteer and ImageMagick


Technology:
SmartContracts, Solidity, ERC-20, ERC-1155, IPFS, HardHat, OpenZeppelin, ImageMagick, Sharp,
Image Manipulation, Generative Art, NFT, Docker, Puppeteer
SmartContracts Solidity ERC-20 ERC-1155 IPFS HardHat OpenZeppelin ImageMagick C# Image Manipulation Generative Art NFT Docker Pupperteer
Berlin
6 months
2022-06 - 2022-11

SmartContracts + d'App for Security Tokens

Lead Software Developer Avalanche SmartContracts Solidity ...
Lead Software Developer
For [Company name on request] and its client Greenrock Energy (Austria & Germany), I developed Smart

Contracts and a corresponding d'App for the management and issuance of Security Tokens on the Polygon Blockchain in accordance with the German Electronic Securities Act ("eWpG").


My tasks in detail:
? Development of the Smart Contracts in Solidity (ERC20 + ERC1155 for Permissions according  to eWpG)
? Development of the d'App for the issuance of shares
? Development of the d'App for the registry law

? Development of the snapshots for the registry excerpt


Technology:

Avalanche, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, eWpG, GeSAct, IPFS


Information about the Project:

? Press Release (https://greenrock.energy/pm-gre-bond-two/)

? Article in Börsen-Zeitung (https://www.boersen-zeitung.de/banken-finanzen/greenrock-lanciert-erste-gruene-anleihe-als-e-wertpapier-a63377a6-ac5d-11ed-96eb-7f4be6535413)

Avalanche SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin eWpG GeSAct IPFS
Berlin
3 months
2022-05 - 2022-07

Wallets As A Service / Custody Services

Lead Software Developer Go TypeScript Node.js ...
Lead Software Developer

For [Company name on request], its clients and its chain backend, we developed Wallet As A Service: a scalable and secure set of wallet infrastructure APIs, enabling companies to create and deploy fully customizable, custodial on-chain wallets to their end users. Companies can offer their users wallets directly in their apps with onboarding as simple as a username and password. As another use case, custody providers can build their product on top of this tack stack, either as Cloud-service or on-premise. Our "Wallets as a Service" allows clients to create and store multiple wallets in distinct vaults. Transactions are first signed within this trusted network before being sent to the blockchain. Key materials are securely retained within the trusted network, never leaving its confines. Advanced cryptographic methods, including key rotation and data key encryption, are employed for enhanced security.


My tasks in detail:
? System architecture & Secured Infrastructure
? Elliptic Curve Cryptography
? Lead Dev of wallet management and cryptographic principles

? Leading the engineering team


Technology:
AWS KMS, Go, TypeScript, NestJS, PostgreSQL, VPN, Elliptic Curves Cryptography,
Hierarchic Deterministic Wallets, BIP-32, BIP-39, BIP-44
Go TypeScript Node.js NestJS Kubernetes AWS KMS JCE VPN BIP-32 BIP-39 BIP-44
Berlin
3 months
2022-05 - 2022-07

SmartContracts + d'App for Tokenization of GmbH shares

Lead Software Developer SmartContracts Solidity ERC-20 ...
Lead Software Developer

For [Company name on request] and our client, Aquaty GmbH, I developed Smart Contracts for the tokenization of GmbH shares, as well as for complex access permission models. In addition, I worked with our team of web specialists to develop a web app for managing all on-chain processes (d'App).


My tasks in detail:

? Development of Smart Contracts in Solidity

? ERC-20, ERC-1410

? Factory Contracts, Whitelisting Contracts, ACL + Permissions on-chain

? Access Control Management for different governance roles

? Development of the web front-end for token "minting"

? Development of the web front-end for managing whitelists on the Smart Contract and for

managing different permission roles.


Technology:

SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS

SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin IPFS
Berlin
2 months
2022-01 - 2022-02

SmartContracts + d'App for Tokenization of Carbon Credits

Lead Software Developer Avalanche SmartContracts Solidity ...
Lead Software Developer

For [Company name on request] and our client, Below2 Inc. (USA), I wrote the Smart Contracts for the tokenization of Carbon Credits, which includes the actual tokens, a vault contract for the retirement of the Carbon Credits, and receipt tokens that are automatically sent back as a receipt for the deposit of the CO2 tokens.


In addition, along with our Web3- and UI team, we developed a d'App for management, the issuance of tokens, as well as for customer-side token retirement.


My tasks in detail:
? Development of the Smart Contracts in Solidity
? ERC20: Carbon Credits
? Custom: Vault Contract for the retirement of Carbon Credits
? ERC20 + ERC1155: Receipt Tokens

? ERC1155: Permissions for the issuance of the Carbon Credit Tokens

? Development of the dApp for the issuance of tokens

? Development of the dApp for the storage ("retirement") of Carbon Tokens


Technology:

Polygon, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS


More information:

? Below2 (https://below2.earth/)

? the underlying suite of SmartContracts, that we wrote for such use-cases, is on GitHub [URL on request]

Avalanche SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin IPFS Polygon
Berlin
5 months
2021-07 - 2021-11

Electronic Securities on Ethereum according to eWpG

Lead Software Developer Ethereum SmartContracts Solidity ...
Lead Software Developer
For Chartered Investment Germany GmbH, Düsseldorf, Smart Contracts and necessary web

applications were developed for a digital security on the Ethereum and Avalanche Blockchains, in accordance with the Electronic Securities Register Act.


The collaboration took place in close coordination with the law firm Lindenpartners, Berlin, to align with the requirements of BaFin and to consider all regulatory aspects.


Proof: https://etherscan.io/address/0x114b42adaa9381b6c60cc408c8b261afa7bcdeac


My tasks in detail:

? Conceptual collaboration regarding the interpretation of eWpG in terms of technological

possibilities and constraints in the Ethereum protocol Development of Smart Contracts

? ERC-20 based Smart Contracts

? ERC-1410 based Smart Contracts

? Factory Contracts + Whitelisting + Blacklisting

? Access Control Management for different governance roles

? Development of the web front-end for token minting

? Development of the web front-end for managing the whitelists on the Smart Contract and for

managing different administrative roles

? Development of a backend for the registry management and determination of token balances per

investor's wallet

? Close cooperation with lawyers in favor of regulatory guidelines


Technology:

SmartContracts, Solidity, ERC-20, ERC-1410, HardHat, OpenZeppelin, Quasar, TypeScript

More Information:


? Article in the Press (https://www.btc-echo.de/news/chartered-investment-begibt-kryptowertpapier-auf-ethereum-130928/)

Ethereum SmartContracts Solidity ERC-20 ERC-1410 dApp HardHat OpenZeppelin eWpG GeSAct Quasar TypeScript
Berlin
1 month
2021-05 - 2021-05

Technical Due Diligence - CEX

***please add*** TechDD
***please add***

As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of FinTech and Blockchain during a technical due diligence of a well-known cryptocurrency exchange. My particular activities included:


? Code Reviews / Auditing
? Interviews with the CTO and CEO
? Developer interviews
? Architecture assessment
? Security assessment around wallet management and blockchain interaction
TechDD
Berlin
1 year 6 months
2019-12 - 2021-05

Initial Token Offering (ICO), Smart Contracts and Token Distribution

Lead Software Developer Ethereum Solidity OpenZeppelin ...
Lead Software Developer

Development and technical preparation of Iron Eagle Capital GmbH's ICO for the in-house Nuco cloud and the NCDT token.


URL: https://nuco.cloud
Smart Contracts: https://github.com/nucocloud/ncd-token
Etherscan: https://etherscan.io/token/0xe0c8b298db4cffe05d1bea0bb1ba414522b33c1b


My Tasks:

? Teambuilding legal framework (external via Lindenpartners/Berlin)
? Development of the Token Sale and Distribution dApp
? Integration of Affiliate programs / bonus programs with multiple levels
? Technological whitepaper support
? Training and ongoing advice to the founding team on blockchain-related topics and on the
technicalities of an ICO
? Distribution platform for token acquisition and investor management
? Supporting the Design of the token economy
? Integrated crypto-payments
? KYC/AML via Fractals

? Fiat-Payment via Micropayment


Ethereum Solidity OpenZeppelin Truffle Web3 ERC-20 Fractals
Berlin
1 month
2021-04 - 2021-04

Technical Due Diligence - FinTech/Hyperledger

***please add*** TechDD
***please add***

As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of Cryptography and Blockchain during a technical due diligence of a FinTech building with Hyperledger. My particular activities included:


? Code Reviews / Auditing
? Interviews with the CTO
? Developer interviews
? Assessment regarding HyperLedger/Swiss Trust Chain and their Chain Code
TechDD
Philipps & Byrne GmbH
Berlin
1 year 6 months
2019-11 - 2021-04

Security Token Offering, Smart Contracts and Token Distribution

Lead Software Developer Ethereum Solidity OpenZeppelin ...
Lead Software Developer
Palmtrip GmbH would like to issue a Security Token with BaFin-Approval. The Security Token will be a regulated security with its own WKN/ISIN. Via the token, dividends will be distributed annually to the token holders via snapshot. Regulatory requirements on the part of BaFin require a special design of the token contracts with regard to transferability. So-called Oracle techniques are used here to link
the on-chain world with the off-chain world.


My Tasks:

? Test-driven development of SmartContracts based on the umbrella standard for security tokens according to ERC 1411 (formerly ERC 1400)
? Token Sale & Distribution dApp
? Distribution platform for token acquisition, investor management and dividend payments
? Consulting around token design in coordination with the lawyers involved regarding legal and technical feasibility
? ERC-20 backward compatible
? Whitelisting for token transfer
? ERC-1594: Core Security Token Standard
? ERC-1410: Partially Fungible Tokens
? ERC-1643: Document Management Standard
? ERC-1644: Controller Token Operation Standard
? Use of Oracles for injecting off-chain KYC into Token Transfers
? Integrated crypto-payments
? Fiat payments via external Payment providers
? Solarisbank Integration
? Uploads of legal documents to IPFS and deposit of hashes in the SmartContracts per token
purchase as part of a partitioning process
Ethereum Solidity OpenZeppelin Truffle Web3 ERC-20 Oracle SQL Developer ERC-1400 ERC-1411 ERC-1410 ERC-1643 ERC-1644 IPFS Solarisbank
PalmTrip GmbH
Rabenau, Hessen
5 months
2019-11 - 2020-03

Research Project Ethereum '19

Lead Software Developer Ethereum Solidity OpemZeppelin ...
Lead Software Developer
Blockchain Research and Development Project in the Independent Automotive Aftermarket (NDA
protected).


Features:

? Consulting around Smart Contracts on the Ethereum Blockchain.
? Development of smart contracts with Solidity
? Research of feasability of the use-cases with regards to Web3-UX and Gas Fees
? Backend + REST API for OnChain operations.
? Gas Fee simulation
? Optimization of smart contracts in terms of memory consumption and fees
? Interaction with the SmartContracts via Web3.js into an existing Angular application
Ethereum Solidity OpemZeppelin Truffle Web3
German Car Manufacturer (NDA)
Berlin
11 months
2019-01 - 2019-11

SaaS Platform ?Blockchain Snapshot as a Service

Lead Software Developer
Lead Software Developer

During the development of our STO launchpad (see below), the so-called snapshotting of the EVM blockchain for dividend or interest payments turned out to be a by-product that we will separate out and market as a separate product in the future.


My tasks:
? Programmatic implementation of "snapshotting" for requested tokens on the Ethereum
blockchain in general.
? Database scheme for time series and big data based on TimescaleDB and PostgreSQL
? Writing PostgreSQL Extensions for this kind of data
? History of token transfers
? REST API
? Own payment system for Bitcoin and Ether payments
? Connections to other banking interfaces for automatic payment of dividends
? Admin dashboard for managing customer data and payments, invoices, etc.


Technology:

Go, EVM, Ethereum, PostgreSQL, REST, Swagger, BigData, TimescaleDB



Go EVM Ethereum PostgreSQL REST Swagger Big Data TimescaleDB
ITinance GmbH
Berlin
1 year 1 month
2018-06 - 2019-06

CTO - YAIR GmbH (Crypto, NFT)

CTO Ethereum Solidity SmartContracts ...
CTO
Founded in 2016, the startup YAIR secures the access and value of digital artworks through
blockchain technology, making digital art accessible and tradable for the art market.
My tasks & responsibilities:
? Ongoing technical consulting of the team and software development around Blockchain,
SmartContracts and the upcoming STO (Security Token Offering).
? Project planning with the team and investors
? Development of the SmartContracts (ERC-721, ERC-20, ERC-1400), backend, marketplace and
mobile apps with Flutter (cross-platform iOS & Android).
? Leading the development of the token sale platform:
? User management
? Artwork management
? Affiliate program / bonus program with different levels
? Token Sale, payment & distribution
? Payment-Methods: ETH, BTC, Aeternity-Token
? Planning and leading the development of the digital art trading platform
? VR app with display connectors to external devices such as Samsung Frame and

other VR headsets.


Technology Stack

? Backend:

? Symfony, Sylius, Doctrine, API Platform, Swagger

? Docker, Kubernetes

? On-chain:

? Ethereum

? Aeternity-Blockchain

? IPFS, StorJ

? Mobile:

? Flutter / Dart

? ReactNative (MVP, migrated to Flutter)

? BLOC, Reactive Programming

? Unity3D

? Vuforia

? ChromeCast

? AWS

? EC2

? S3, Cloudfront

Ethereum Solidity SmartContracts Aeternity Flutter SAP DART PHP IPFS StorJ SWIFT Objective-C C++ ChromeCast Unity3D Symfony Sylius Swagger
YAIR GmbH
Berlin
1 month
2018-08 - 2018-08

Modernization / Refactoring of an eCommerce Startup

Lead Software Developer Magento Shopware PHP ...
Lead Software Developer

For this German  startup with a code base that was over 10 years old, a step-by-step decoupling of the legacy monolith into a complete separation of frontend, backend, database layer and other services (analytics, API connections, client connection) was carried out.

The focus here was on the ongoing separation of individual software components into the new architecture and the encapsulation of fragile, security-relevant legacy elements in secure containers to enable a seamless, gradual transition of the legacy architecture into the new architecture.

Similarly, an optimization of the product search function was implemented using ElasticSearch.

Technology-Stack:

  • PHP
  • MySQL
  • Magento
  • Wordpress
  • ElasticSearch
  • Symfony
  • Docker
  • Swagger
  • Behat
  • Logstash & Kibana
Magento Shopware PHP MySQL Elastic Search E-Commerce Refactoring Migration Amazon Payments LogStash Kibana
ITinance GmbH
Berlin
1 month
2018-06 - 2018-06

Technical Due Diligence - Travel-Tech, Asia

***please add*** TechDD Technical Due Diligence Tech Interview ...
***please add***

Analysis and auditing of the software structure and quality of a startup in the field of online travel services for the Southeast Asian region based in Kuala Lumpur / Malaysia.


  • Code base & packager:
    • React, ES6/ES7, JSX, Webpack, Babel
  • Data-Layer:
    • graphQL, relay
  • Frontend:
    • Express, Materialize, PostCSS
  • Authentication:
    • auth0.com
TechDD Technical Due Diligence Tech Interview Lieferantenbewertung Code Review Audit ReactJS GraphQL Auth0 Vorwerk
NFQ Asia
Berlin

Kompetenzen

Kompetenzen

Top-Skills

Go PHP Solidity Postgres Python Machine Learning TypeScript NodeJS Symfony Sylius MySQL NestJS SmartContracts Softwarearchitektur CI/CD Kubernetes Docker Qdrant Vector databases Embeddings vLLM C++ C#

Produkte / Standards / Erfahrungen / Methoden

Professional Summary:

  • With over three decades of software development experience, I have a profound background in sectors such as FinTech, Blockchain, and previously, eCommerce
  • In 2021, I developed the very first Smart Contract for Security Tokens according to eWpG (German Electronics Securities Act) and presented the Contracts to responsible employees of BaFin
  • My passion for backend development and SmartContracts is demonstrated by my active contributions to OpenSource projects and my six-year tenure in the Blockchain industry
  • This is complemented by five years of experience in mobile development
  • Over the years, I've transitioned into leadership roles, with a well-rounded decade serving as a Chief Technology Officer (CTO)
  • Beyond my technical proficiencies, I have significant experience in the startup ecosystem, showcasing my entrepreneurial flair through the co-founding of multiple fintech and ed-tech startups
  • Notably, one of these ventures achieved a successful exit
  • In previous roles as a team and developer lead, I honed my abilities to build, inspire, and drive high-performing teams
  • In addition to my technical skills, I have engaged directly with lawyers on issues of compliance and European regulation within the blockchain and financial sectors, emphasizing my comprehensive understanding of this industry's legal framework


Skills:

  • Team Building 
  • Engineering 
  • Blockchain Development 
  • Smart Contracts
  • Web3 
  • Compliance 
  • Regulated Environments 
  • Company Building
  • Software Architecture 
  • Positive Mindset 
  • High-Performance Teams 
  • Scalability


Technical Skills

  • Go 
  • Solidity
  • Smart Contracts
  • TypeScript
  • NodeJS
  • Kubernetes
  • Relational Databases
  • PHP
  • Technical Due Diligence 
  • DevOps
  • Infrastructure 
  • AWS


Work Experience:

2021 - today

Place of Work: Berlin

Customer: on Request

Role: CTO & Co-Founder 


Tasks:

  • I've led the growth of the Engineering Team from inception, personally increasing its size from a single developer to 15 dedicated professionals.
  • In this role, I've also successfully set up a robust software architecture, and continuously educated the team on complex web3 and blockchain-related topics, thereby contributing significantly to our mission of creating an all-in-one software solution for tokenizing real-world assets



2020 - 2021

Place of Work: Switzerland

Customer: on Request

Role: CTO & Co-Founder 2020 ?2021


Tasks:

  • As the foundational leader of the engineering team at an e-Money-based core banking system startup, I grew the team from the ground up to five engineers, successfully ensuring the timely release of our first software version in production
  • Our product, a reward-based payment system for eCommerce companies, was instrumental to the successful exit of the company within just one year
  • Our product, a reward-based payment system for eCommerce companies, was instrumental to the successful exit of the company within just one year


2018 - 2019

Place of Work: Berlin

Role: Engineering & CTO 

Customer: Yair GmbH


Tasks:

  • At YAIR, I led the formation of the engineering team and successfully facilitated the release of our blockchain-secured, gamified platform for the new media art market in both Android and iOS app stores within a year
  • Our innovative application revolutionized the distribution, authentication, preservation, and trading of new media arts globally


2011 - 2018

Place of Work: Düsseldorf, München, Berlin

Role:Founder, Engineering, Interims-CTO 

Customer: on Request


Tasks:

  • With proven expertise in developing blockchain products and token ecosystems on various chains including Ethereum, I've delivered innovative solutions for smart contract interaction and crypto-payment integration in eCommerce software, including the creation of our own token sale and distribution platform.
  • My earlier experience includes building mobile applications and providing strategic consulting and software refactoring services for mid-sized organizations


2016 - 2018

Place of Work: Salt Lake City (USA)

Role: CTO & Co-Founder 2016 ?2018

Customer: on Request 


Tasks:

  • As part of the BOOM startup cohort, I led the swift development of our application's backend and frontend, including the production of iOS and Android apps, all within a tight two-month period
  • In parallel, I successfully built a cohesive and effective engineering team of two


2014 - 2015

Place of Work: Munich

Role:Team Lead Engineering

Customer: Yatego GmbH, 


Tasks:

  • As team lead for YategoLocal I was in charge of the engineering team and the development of App development as well the backend


2013 - 2014

Place of Work: Munich

Role: Senior Software Engineer Backend 

Customer: Yatego GmbH


Tasks:

  • I was part of the refactoring team where the whole software stack of Yatego's eCommerce platform has been rebuilt


Software Engineer Backend + Web Development 2011 - 2013

Amakura GmbH, Cologne

With a team of 6 developers we built a web-based ERP software for the insurance sector.


2011 - 2012

Place of Work: Meerbusch/Duesseldorf

Role: CTO / Lead Dev,

Customer: medolan UG


Tasks:

  • As the leading software developer for this eHealth Startup based in Düsseldorf (Germany) I was responsible for the development of the whole software stack


2008 - 2011

Place of Work: Duesseldorf

Role: Software Developer (ASP.Net) 

Customer: Chronocycle Solutions GmbH


Tasks:

  • With a team of 6 developers we built a web-based ERP software for the insurance sector
  • Besides the integration of finance-related interfaces and data imports like MT940 and DTAUS, I was responsible for performance optimizations, for both frontend and backend, particularly the Microsoft SQL Server database


2005 - 2007

Place of Work: Cologne

Role: Web Developer Marketplace 

Customer: Sedo GmbH


Tasks:

  • I was a member of the web application development team and amongst other things responsible for the development of the real-time auction system and several backend tools


1998 - 2005

Place of Work: Cologne

Role: Software Developer 

Customer: LECTOR Computersysteme GmbH

Branchen

Branchen

In addition to my technical skills, I have engaged directly with lawyers during recent years on compliance issues and European regulation within the blockchain and financial sectors, emphasizing my comprehensive understanding of this industry's legal framework and processes in the environment of Banking and Insurance.


Furthermore, I am familiar with processes and legal aspects in eCommerce and GDPR. I am still not a lawyer, but I talked to them a lot to understand the important things.

Einsatzorte

Einsatzorte

Berlin (+100km) Munich (+50km)
Deutschland, Österreich
möglich

Projekte

Projekte

11 months
2024-01 - now

NLP + Machine Learning + Backend + Big Data at AI Startup

Fullstack Engineer + Architect Python Qdrant PostgreSQL ...
Fullstack Engineer + Architect

Lead Engineer & Architect | Backend, Frontend, and ML Team Leader

As the first engineer and architect on this project, I have been instrumental in shaping the system from the ground up. My role spans across backend development, leading a multi-functional team (backend, frontend, ML), and overseeing the architecture of microservices-based systems.

Our technology stack includes Python and NestJS for backend services, while the frontends leverage the Quasar Framework and NextJS. We also manage on-premise GPUs to securely host large language models (LLMs), ensuring data protection for our users.

We run Postgres and Qdrant databases with > 1 TB of data.

I bring a deep expertise in full-stack development, system architecture, and team leadership, with a focus on scalability, security, and innovative AI-driven solutions.

Python Qdrant PostgreSQL Node.js TypeScript NestJS NextJS Quasar Framework vLLM CUDA GPU
infobud GmbH
Berlin
2 years 4 months
2021-07 - 2023-10

Software Suite for Tokenization of Digital Assets

Lead Software Developer Go Solidity Node.js ...
Lead Software Developer

For the clients of [Company name on request] from the financial market, we are developing a product suite with a team of software developers, UX specialists, and lawyers, which allows issuers to emit and manage digital assets at the blockchain level. This includes:

  • Asset Management
  • Investor Management
  • Investor Dashboard
  • Fully automated handling of tokenization (Minting, Transfer, Burn)
  • Registry extracts
  • Payment options including Stripe, PayPal and cryptocurrencies
  • Invoice-Management
  • Automated dividend and interest payouts
  • Cryptocurrency processing
  • Minting Studio for issuing and distributing tokens

  • Software Architecture
  • Leading the Engineering team incl. DevOps
  • Backend Development
  • Development of On-Chain components (SmartContracts, dApps-Connectivity, RPC-APIs)

Go Solidity Node.js PHP Sylius Symfony NestJS Ethereum Ethers IPFS Web3 SmartContracts Stripe PayPal MySQL PostgreSQL Docker Kubernetes RabbitMQ Prometheus Grafana Graylog
tokenforge GmbH
Berlin
3 years 10 months
2020-01 - 2023-10

eMoney Payment Gateway API, weeCommerce AG

Lead Software Developer Go nats.io ProtoBuf ...
Lead Software Developer

As a joint project with our client weeCommerce AG, we created a Payment Gateway that can handle the complete payment processing within the framework of a WhiteLabel Banking System. The following features are provided within a REST API:


Features:
? Account opening for both private and business customers (Europe-wide)
? KYC (Know Your Customer)
? UBO (Ultimate Beneficiary Owner Check)
? Deposits of credit into internal eMoney-based wallets
? Withdrawals of credit to bank accounts via IBAN
? Transactions between wallets
? Bulk transactions between different wallets as individual transactions
? Credit Card Payments including 3DSecure


My tasks and responsibilities:

? Team Building
? Development of the entire software architecture and the final technology stack
? Technical Product Owner
? Development of the banking engine and the REST-API in Go
? Team coordination in collaboration with other developers
? Planning and coordination of peripherals (dashboards, monitoring, recovery)


Technology:

Go (Backend, Services, REST-API), nats.io (message bus), ProtoBuf (data layer / protocol),
PostgreSQL, Prometheus, Grafana, GrayLog / ElasticSearch, Traeffik, KeyCloak, Kubernetes, ReactJS for Admin-Dashboard
Go nats.io ProtoBuf Kubernetes PostgreSQL Prometheus Grafana Graylog Traeffik KeyCloak ReactJS CSPO
Berlin
4 months
2023-06 - 2023-09

Avalanche SubNet for a custom EVM-blockchain

Lead Software Developer Avalanche Go EVM ...
Lead Software Developer

Problem: 

Facing difficulties acquiring test-tokens due to drained faucets on various blockchains such

as Goerli and Polygon, my team and I frequently encountered obstacles during product testing, development, and demonstration. To circumvent these challenges, we decided to create our own EVM blockchain using Avalanche SubNets, providing us with robust Testnets to experiment with the deployment of SmartContracts, token interactions, and the minting of various token types, such as NFTs, SecurityTokens, and ReFi components.


Solution: 

Now we proudly manage our own chains, run our own faucet, operate our own block explorer via Blockscout, and, with immense gratitude to the open-source community, we even have our own SmartContract execution tool, which delivers a user experience surpassing that offered by Etherscan and its counterparts. 


Technology:

Avalanche, Go, EVM, SubNet, Blockscout, Kubernetes, DevOps


More information can be found here:
? Article on LinkedIn: [Title and URL on request]
Avalanche Go EVM SubNet Blockscout Kubernetes DevOps
Berlin
9 months
2023-01 - 2023-09

SmartContracts + d'App for Security Tokens (eWpG)

Lead Software Developer Solidity Blockchain Ethereum ...
Lead Software Developer

For [Company name on request] and its client, Chartered Investment AG & eSec, a registrar for Security Tokens, I wrote Smart Contracts and a corresponding d'App for the management and issuance of Security Tokens on the Avalanche Blockchain in accordance with the German Electronic Securities Act ("eWpG").


  • Development of the Smart Contracts in Solidity (ERC20 + ERC1155 for Permissions according to eWpG) 
  • Development of the d'App for the issuance of shares
  • Development of the d'App for the registry law
  • Development of the snapshots for the registry excerpt


Avalanche, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS


  • Announcement on Twitter  [URL on request]
  • BaFin - official record  (https://www.bafin.de/DE/PublikationenDaten/Datenbanken/Kryptowertpapiere/kryptowertpapiere_artikel.html)
  • Press Release  (https://chartered-investment.com/en/media/news/chartered-investment-und-smart-wealth-lancieren-ersten-tokenisierten-index-tracker-unter-ewpg/)
  • Contract Address  [URL on request]
Solidity Blockchain Ethereum Avalanche Polygon VueJS dApp SmartContracts ERC-20 ERC-1155 HardHat OpenZeppelin eWpG GeSAct IPFS
Berlin
2 years 3 months
2021-07 - 2023-09

Tokenization Platform for Real-World Assets (RWA)

Lead Software Developer Go Node.js TypeScript ...
Lead Software Developer

[Company name on request] is a Berlin-based technology provider that offers its customers a software toolkit for asset tokenization, that offers the possibility to tokenize assets compliant with the law, fully digital and with no code.


For [Company name on request] and its clients, we developed an All-in-one toolkit for Security Token Issuance:


The Security Token Suite enables fast, legally compliant and secure issuance of bonds and digital

securities:


? MiFiD II compliant underwriting process
? Fully automated token- and wallet generation
? Admin dashboard for efficient data- and issuance management

? eCommerce-like experience for investors

? Integration of KYC/AML, UBO and payment providers

? Stable and reliable token-minting experience

? Fully automated and scalable token issuance + transferability

? Automated token distribution

? API First Approach (Launchpad-API | Chain-API)

? Wallets as a Service (our own custody provider)

? Integration of external Custody-Providers


My tasks in detail:

? Software Architecture (Microservices)

? Team-Lead Engineering at the beginning, followed by a typical CTO-Role

? Software Development on all levels

? Cryptography

? On-Chain-/Web3 development

? Backend engineering

? Setup Infrastructure with DevOps


Technology:

Go, NodeJS, TypeScript, NestJS, PostgreSQL, SmartContracts, Solidity, PHP, Ethereum, Avalanche, Polygon, AWS KMS, Cryptography, Kubernetes, RabbitMQ, Redis, Prometheus, Graylog, Grafana, ERC-20, ERC-1155, ERC-721, BIP-32, BIP-44

Go Node.js TypeScript NestJS PostgreSQL SmartContracts Solidity PHP Ethereum Avalanche Polygon AWS KMS JCE Kubernetes Prometheus Graylog Grafana RabbitMQ Redis ERC-20 ERC-1155 ERC-721 BIP-32 BIP-44
Berlin
1 month
2022-12 - 2022-12

Technical Due Diligence - Cryptography & Blockchain

Consultant TechDD Cryptography Blockchain ...
Consultant
As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of Cryptography and Blockchain during a technical due diligence of a crypto-related company. 


My particular activities included:

? Code Reviews / Auditing
? Interviews with the CTO
? Developer interviews
? Architecture assessment
TechDD Cryptography Blockchain Distributed Ledger Distributed FileSystem StorJ
Philipps & Byrne GmbH
Berlin
1 year 6 months
2021-07 - 2022-12

SmartContracts for various NFT-projects

Lead Software Developer SmartContracts Solidity ERC-20 ...
Lead Software Developer

For [Company name on request] and its clients, I continually developed Smart Contracts for various approaches revolving around NFT and utility tokens with full test-overage. In addition, I developed a centralized backend to make the management of on-chain processes accessible via a REST API (keyword ?Web 2.5?).


My tasks in detail:
? Smart Contracts in Solidity based on:
? ERC-20
? ERC-721
? ERC-1155
? Tools for minting tokens
? Tools for managing metadata and files on IPFS

? Image processing/manipulation for generative Art using Puppeteer and ImageMagick


Technology:
SmartContracts, Solidity, ERC-20, ERC-1155, IPFS, HardHat, OpenZeppelin, ImageMagick, Sharp,
Image Manipulation, Generative Art, NFT, Docker, Puppeteer
SmartContracts Solidity ERC-20 ERC-1155 IPFS HardHat OpenZeppelin ImageMagick C# Image Manipulation Generative Art NFT Docker Pupperteer
Berlin
6 months
2022-06 - 2022-11

SmartContracts + d'App for Security Tokens

Lead Software Developer Avalanche SmartContracts Solidity ...
Lead Software Developer
For [Company name on request] and its client Greenrock Energy (Austria & Germany), I developed Smart

Contracts and a corresponding d'App for the management and issuance of Security Tokens on the Polygon Blockchain in accordance with the German Electronic Securities Act ("eWpG").


My tasks in detail:
? Development of the Smart Contracts in Solidity (ERC20 + ERC1155 for Permissions according  to eWpG)
? Development of the d'App for the issuance of shares
? Development of the d'App for the registry law

? Development of the snapshots for the registry excerpt


Technology:

Avalanche, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, eWpG, GeSAct, IPFS


Information about the Project:

? Press Release (https://greenrock.energy/pm-gre-bond-two/)

? Article in Börsen-Zeitung (https://www.boersen-zeitung.de/banken-finanzen/greenrock-lanciert-erste-gruene-anleihe-als-e-wertpapier-a63377a6-ac5d-11ed-96eb-7f4be6535413)

Avalanche SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin eWpG GeSAct IPFS
Berlin
3 months
2022-05 - 2022-07

Wallets As A Service / Custody Services

Lead Software Developer Go TypeScript Node.js ...
Lead Software Developer

For [Company name on request], its clients and its chain backend, we developed Wallet As A Service: a scalable and secure set of wallet infrastructure APIs, enabling companies to create and deploy fully customizable, custodial on-chain wallets to their end users. Companies can offer their users wallets directly in their apps with onboarding as simple as a username and password. As another use case, custody providers can build their product on top of this tack stack, either as Cloud-service or on-premise. Our "Wallets as a Service" allows clients to create and store multiple wallets in distinct vaults. Transactions are first signed within this trusted network before being sent to the blockchain. Key materials are securely retained within the trusted network, never leaving its confines. Advanced cryptographic methods, including key rotation and data key encryption, are employed for enhanced security.


My tasks in detail:
? System architecture & Secured Infrastructure
? Elliptic Curve Cryptography
? Lead Dev of wallet management and cryptographic principles

? Leading the engineering team


Technology:
AWS KMS, Go, TypeScript, NestJS, PostgreSQL, VPN, Elliptic Curves Cryptography,
Hierarchic Deterministic Wallets, BIP-32, BIP-39, BIP-44
Go TypeScript Node.js NestJS Kubernetes AWS KMS JCE VPN BIP-32 BIP-39 BIP-44
Berlin
3 months
2022-05 - 2022-07

SmartContracts + d'App for Tokenization of GmbH shares

Lead Software Developer SmartContracts Solidity ERC-20 ...
Lead Software Developer

For [Company name on request] and our client, Aquaty GmbH, I developed Smart Contracts for the tokenization of GmbH shares, as well as for complex access permission models. In addition, I worked with our team of web specialists to develop a web app for managing all on-chain processes (d'App).


My tasks in detail:

? Development of Smart Contracts in Solidity

? ERC-20, ERC-1410

? Factory Contracts, Whitelisting Contracts, ACL + Permissions on-chain

? Access Control Management for different governance roles

? Development of the web front-end for token "minting"

? Development of the web front-end for managing whitelists on the Smart Contract and for

managing different permission roles.


Technology:

SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS

SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin IPFS
Berlin
2 months
2022-01 - 2022-02

SmartContracts + d'App for Tokenization of Carbon Credits

Lead Software Developer Avalanche SmartContracts Solidity ...
Lead Software Developer

For [Company name on request] and our client, Below2 Inc. (USA), I wrote the Smart Contracts for the tokenization of Carbon Credits, which includes the actual tokens, a vault contract for the retirement of the Carbon Credits, and receipt tokens that are automatically sent back as a receipt for the deposit of the CO2 tokens.


In addition, along with our Web3- and UI team, we developed a d'App for management, the issuance of tokens, as well as for customer-side token retirement.


My tasks in detail:
? Development of the Smart Contracts in Solidity
? ERC20: Carbon Credits
? Custom: Vault Contract for the retirement of Carbon Credits
? ERC20 + ERC1155: Receipt Tokens

? ERC1155: Permissions for the issuance of the Carbon Credit Tokens

? Development of the dApp for the issuance of tokens

? Development of the dApp for the storage ("retirement") of Carbon Tokens


Technology:

Polygon, SmartContracts, Solidity, ERC-20, ERC-1155, HardHat, OpenZeppelin, IPFS


More information:

? Below2 (https://below2.earth/)

? the underlying suite of SmartContracts, that we wrote for such use-cases, is on GitHub [URL on request]

Avalanche SmartContracts Solidity ERC-20 ERC-1155 HardHat OpenZeppelin IPFS Polygon
Berlin
5 months
2021-07 - 2021-11

Electronic Securities on Ethereum according to eWpG

Lead Software Developer Ethereum SmartContracts Solidity ...
Lead Software Developer
For Chartered Investment Germany GmbH, Düsseldorf, Smart Contracts and necessary web

applications were developed for a digital security on the Ethereum and Avalanche Blockchains, in accordance with the Electronic Securities Register Act.


The collaboration took place in close coordination with the law firm Lindenpartners, Berlin, to align with the requirements of BaFin and to consider all regulatory aspects.


Proof: https://etherscan.io/address/0x114b42adaa9381b6c60cc408c8b261afa7bcdeac


My tasks in detail:

? Conceptual collaboration regarding the interpretation of eWpG in terms of technological

possibilities and constraints in the Ethereum protocol Development of Smart Contracts

? ERC-20 based Smart Contracts

? ERC-1410 based Smart Contracts

? Factory Contracts + Whitelisting + Blacklisting

? Access Control Management for different governance roles

? Development of the web front-end for token minting

? Development of the web front-end for managing the whitelists on the Smart Contract and for

managing different administrative roles

? Development of a backend for the registry management and determination of token balances per

investor's wallet

? Close cooperation with lawyers in favor of regulatory guidelines


Technology:

SmartContracts, Solidity, ERC-20, ERC-1410, HardHat, OpenZeppelin, Quasar, TypeScript

More Information:


? Article in the Press (https://www.btc-echo.de/news/chartered-investment-begibt-kryptowertpapier-auf-ethereum-130928/)

Ethereum SmartContracts Solidity ERC-20 ERC-1410 dApp HardHat OpenZeppelin eWpG GeSAct Quasar TypeScript
Berlin
1 month
2021-05 - 2021-05

Technical Due Diligence - CEX

***please add*** TechDD
***please add***

As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of FinTech and Blockchain during a technical due diligence of a well-known cryptocurrency exchange. My particular activities included:


? Code Reviews / Auditing
? Interviews with the CTO and CEO
? Developer interviews
? Architecture assessment
? Security assessment around wallet management and blockchain interaction
TechDD
Berlin
1 year 6 months
2019-12 - 2021-05

Initial Token Offering (ICO), Smart Contracts and Token Distribution

Lead Software Developer Ethereum Solidity OpenZeppelin ...
Lead Software Developer

Development and technical preparation of Iron Eagle Capital GmbH's ICO for the in-house Nuco cloud and the NCDT token.


URL: https://nuco.cloud
Smart Contracts: https://github.com/nucocloud/ncd-token
Etherscan: https://etherscan.io/token/0xe0c8b298db4cffe05d1bea0bb1ba414522b33c1b


My Tasks:

? Teambuilding legal framework (external via Lindenpartners/Berlin)
? Development of the Token Sale and Distribution dApp
? Integration of Affiliate programs / bonus programs with multiple levels
? Technological whitepaper support
? Training and ongoing advice to the founding team on blockchain-related topics and on the
technicalities of an ICO
? Distribution platform for token acquisition and investor management
? Supporting the Design of the token economy
? Integrated crypto-payments
? KYC/AML via Fractals

? Fiat-Payment via Micropayment


Ethereum Solidity OpenZeppelin Truffle Web3 ERC-20 Fractals
Berlin
1 month
2021-04 - 2021-04

Technical Due Diligence - FinTech/Hyperledger

***please add*** TechDD
***please add***

As a member of a technical expert advisory consortium supporting Philips & Byrne, I had the privilege to support them specifically in the areas of Cryptography and Blockchain during a technical due diligence of a FinTech building with Hyperledger. My particular activities included:


? Code Reviews / Auditing
? Interviews with the CTO
? Developer interviews
? Assessment regarding HyperLedger/Swiss Trust Chain and their Chain Code
TechDD
Philipps & Byrne GmbH
Berlin
1 year 6 months
2019-11 - 2021-04

Security Token Offering, Smart Contracts and Token Distribution

Lead Software Developer Ethereum Solidity OpenZeppelin ...
Lead Software Developer
Palmtrip GmbH would like to issue a Security Token with BaFin-Approval. The Security Token will be a regulated security with its own WKN/ISIN. Via the token, dividends will be distributed annually to the token holders via snapshot. Regulatory requirements on the part of BaFin require a special design of the token contracts with regard to transferability. So-called Oracle techniques are used here to link
the on-chain world with the off-chain world.


My Tasks:

? Test-driven development of SmartContracts based on the umbrella standard for security tokens according to ERC 1411 (formerly ERC 1400)
? Token Sale & Distribution dApp
? Distribution platform for token acquisition, investor management and dividend payments
? Consulting around token design in coordination with the lawyers involved regarding legal and technical feasibility
? ERC-20 backward compatible
? Whitelisting for token transfer
? ERC-1594: Core Security Token Standard
? ERC-1410: Partially Fungible Tokens
? ERC-1643: Document Management Standard
? ERC-1644: Controller Token Operation Standard
? Use of Oracles for injecting off-chain KYC into Token Transfers
? Integrated crypto-payments
? Fiat payments via external Payment providers
? Solarisbank Integration
? Uploads of legal documents to IPFS and deposit of hashes in the SmartContracts per token
purchase as part of a partitioning process
Ethereum Solidity OpenZeppelin Truffle Web3 ERC-20 Oracle SQL Developer ERC-1400 ERC-1411 ERC-1410 ERC-1643 ERC-1644 IPFS Solarisbank
PalmTrip GmbH
Rabenau, Hessen
5 months
2019-11 - 2020-03

Research Project Ethereum '19

Lead Software Developer Ethereum Solidity OpemZeppelin ...
Lead Software Developer
Blockchain Research and Development Project in the Independent Automotive Aftermarket (NDA
protected).


Features:

? Consulting around Smart Contracts on the Ethereum Blockchain.
? Development of smart contracts with Solidity
? Research of feasability of the use-cases with regards to Web3-UX and Gas Fees
? Backend + REST API for OnChain operations.
? Gas Fee simulation
? Optimization of smart contracts in terms of memory consumption and fees
? Interaction with the SmartContracts via Web3.js into an existing Angular application
Ethereum Solidity OpemZeppelin Truffle Web3
German Car Manufacturer (NDA)
Berlin
11 months
2019-01 - 2019-11

SaaS Platform ?Blockchain Snapshot as a Service

Lead Software Developer
Lead Software Developer

During the development of our STO launchpad (see below), the so-called snapshotting of the EVM blockchain for dividend or interest payments turned out to be a by-product that we will separate out and market as a separate product in the future.


My tasks:
? Programmatic implementation of "snapshotting" for requested tokens on the Ethereum
blockchain in general.
? Database scheme for time series and big data based on TimescaleDB and PostgreSQL
? Writing PostgreSQL Extensions for this kind of data
? History of token transfers
? REST API
? Own payment system for Bitcoin and Ether payments
? Connections to other banking interfaces for automatic payment of dividends
? Admin dashboard for managing customer data and payments, invoices, etc.


Technology:

Go, EVM, Ethereum, PostgreSQL, REST, Swagger, BigData, TimescaleDB



Go EVM Ethereum PostgreSQL REST Swagger Big Data TimescaleDB
ITinance GmbH
Berlin
1 year 1 month
2018-06 - 2019-06

CTO - YAIR GmbH (Crypto, NFT)

CTO Ethereum Solidity SmartContracts ...
CTO
Founded in 2016, the startup YAIR secures the access and value of digital artworks through
blockchain technology, making digital art accessible and tradable for the art market.
My tasks & responsibilities:
? Ongoing technical consulting of the team and software development around Blockchain,
SmartContracts and the upcoming STO (Security Token Offering).
? Project planning with the team and investors
? Development of the SmartContracts (ERC-721, ERC-20, ERC-1400), backend, marketplace and
mobile apps with Flutter (cross-platform iOS & Android).
? Leading the development of the token sale platform:
? User management
? Artwork management
? Affiliate program / bonus program with different levels
? Token Sale, payment & distribution
? Payment-Methods: ETH, BTC, Aeternity-Token
? Planning and leading the development of the digital art trading platform
? VR app with display connectors to external devices such as Samsung Frame and

other VR headsets.


Technology Stack

? Backend:

? Symfony, Sylius, Doctrine, API Platform, Swagger

? Docker, Kubernetes

? On-chain:

? Ethereum

? Aeternity-Blockchain

? IPFS, StorJ

? Mobile:

? Flutter / Dart

? ReactNative (MVP, migrated to Flutter)

? BLOC, Reactive Programming

? Unity3D

? Vuforia

? ChromeCast

? AWS

? EC2

? S3, Cloudfront

Ethereum Solidity SmartContracts Aeternity Flutter SAP DART PHP IPFS StorJ SWIFT Objective-C C++ ChromeCast Unity3D Symfony Sylius Swagger
YAIR GmbH
Berlin
1 month
2018-08 - 2018-08

Modernization / Refactoring of an eCommerce Startup

Lead Software Developer Magento Shopware PHP ...
Lead Software Developer

For this German  startup with a code base that was over 10 years old, a step-by-step decoupling of the legacy monolith into a complete separation of frontend, backend, database layer and other services (analytics, API connections, client connection) was carried out.

The focus here was on the ongoing separation of individual software components into the new architecture and the encapsulation of fragile, security-relevant legacy elements in secure containers to enable a seamless, gradual transition of the legacy architecture into the new architecture.

Similarly, an optimization of the product search function was implemented using ElasticSearch.

Technology-Stack:

  • PHP
  • MySQL
  • Magento
  • Wordpress
  • ElasticSearch
  • Symfony
  • Docker
  • Swagger
  • Behat
  • Logstash & Kibana
Magento Shopware PHP MySQL Elastic Search E-Commerce Refactoring Migration Amazon Payments LogStash Kibana
ITinance GmbH
Berlin
1 month
2018-06 - 2018-06

Technical Due Diligence - Travel-Tech, Asia

***please add*** TechDD Technical Due Diligence Tech Interview ...
***please add***

Analysis and auditing of the software structure and quality of a startup in the field of online travel services for the Southeast Asian region based in Kuala Lumpur / Malaysia.


  • Code base & packager:
    • React, ES6/ES7, JSX, Webpack, Babel
  • Data-Layer:
    • graphQL, relay
  • Frontend:
    • Express, Materialize, PostCSS
  • Authentication:
    • auth0.com
TechDD Technical Due Diligence Tech Interview Lieferantenbewertung Code Review Audit ReactJS GraphQL Auth0 Vorwerk
NFQ Asia
Berlin

Kompetenzen

Kompetenzen

Top-Skills

Go PHP Solidity Postgres Python Machine Learning TypeScript NodeJS Symfony Sylius MySQL NestJS SmartContracts Softwarearchitektur CI/CD Kubernetes Docker Qdrant Vector databases Embeddings vLLM C++ C#

Produkte / Standards / Erfahrungen / Methoden

Professional Summary:

  • With over three decades of software development experience, I have a profound background in sectors such as FinTech, Blockchain, and previously, eCommerce
  • In 2021, I developed the very first Smart Contract for Security Tokens according to eWpG (German Electronics Securities Act) and presented the Contracts to responsible employees of BaFin
  • My passion for backend development and SmartContracts is demonstrated by my active contributions to OpenSource projects and my six-year tenure in the Blockchain industry
  • This is complemented by five years of experience in mobile development
  • Over the years, I've transitioned into leadership roles, with a well-rounded decade serving as a Chief Technology Officer (CTO)
  • Beyond my technical proficiencies, I have significant experience in the startup ecosystem, showcasing my entrepreneurial flair through the co-founding of multiple fintech and ed-tech startups
  • Notably, one of these ventures achieved a successful exit
  • In previous roles as a team and developer lead, I honed my abilities to build, inspire, and drive high-performing teams
  • In addition to my technical skills, I have engaged directly with lawyers on issues of compliance and European regulation within the blockchain and financial sectors, emphasizing my comprehensive understanding of this industry's legal framework


Skills:

  • Team Building 
  • Engineering 
  • Blockchain Development 
  • Smart Contracts
  • Web3 
  • Compliance 
  • Regulated Environments 
  • Company Building
  • Software Architecture 
  • Positive Mindset 
  • High-Performance Teams 
  • Scalability


Technical Skills

  • Go 
  • Solidity
  • Smart Contracts
  • TypeScript
  • NodeJS
  • Kubernetes
  • Relational Databases
  • PHP
  • Technical Due Diligence 
  • DevOps
  • Infrastructure 
  • AWS


Work Experience:

2021 - today

Place of Work: Berlin

Customer: on Request

Role: CTO & Co-Founder 


Tasks:

  • I've led the growth of the Engineering Team from inception, personally increasing its size from a single developer to 15 dedicated professionals.
  • In this role, I've also successfully set up a robust software architecture, and continuously educated the team on complex web3 and blockchain-related topics, thereby contributing significantly to our mission of creating an all-in-one software solution for tokenizing real-world assets



2020 - 2021

Place of Work: Switzerland

Customer: on Request

Role: CTO & Co-Founder 2020 ?2021


Tasks:

  • As the foundational leader of the engineering team at an e-Money-based core banking system startup, I grew the team from the ground up to five engineers, successfully ensuring the timely release of our first software version in production
  • Our product, a reward-based payment system for eCommerce companies, was instrumental to the successful exit of the company within just one year
  • Our product, a reward-based payment system for eCommerce companies, was instrumental to the successful exit of the company within just one year


2018 - 2019

Place of Work: Berlin

Role: Engineering & CTO 

Customer: Yair GmbH


Tasks:

  • At YAIR, I led the formation of the engineering team and successfully facilitated the release of our blockchain-secured, gamified platform for the new media art market in both Android and iOS app stores within a year
  • Our innovative application revolutionized the distribution, authentication, preservation, and trading of new media arts globally


2011 - 2018

Place of Work: Düsseldorf, München, Berlin

Role:Founder, Engineering, Interims-CTO 

Customer: on Request


Tasks:

  • With proven expertise in developing blockchain products and token ecosystems on various chains including Ethereum, I've delivered innovative solutions for smart contract interaction and crypto-payment integration in eCommerce software, including the creation of our own token sale and distribution platform.
  • My earlier experience includes building mobile applications and providing strategic consulting and software refactoring services for mid-sized organizations


2016 - 2018

Place of Work: Salt Lake City (USA)

Role: CTO & Co-Founder 2016 ?2018

Customer: on Request 


Tasks:

  • As part of the BOOM startup cohort, I led the swift development of our application's backend and frontend, including the production of iOS and Android apps, all within a tight two-month period
  • In parallel, I successfully built a cohesive and effective engineering team of two


2014 - 2015

Place of Work: Munich

Role:Team Lead Engineering

Customer: Yatego GmbH, 


Tasks:

  • As team lead for YategoLocal I was in charge of the engineering team and the development of App development as well the backend


2013 - 2014

Place of Work: Munich

Role: Senior Software Engineer Backend 

Customer: Yatego GmbH


Tasks:

  • I was part of the refactoring team where the whole software stack of Yatego's eCommerce platform has been rebuilt


Software Engineer Backend + Web Development 2011 - 2013

Amakura GmbH, Cologne

With a team of 6 developers we built a web-based ERP software for the insurance sector.


2011 - 2012

Place of Work: Meerbusch/Duesseldorf

Role: CTO / Lead Dev,

Customer: medolan UG


Tasks:

  • As the leading software developer for this eHealth Startup based in Düsseldorf (Germany) I was responsible for the development of the whole software stack


2008 - 2011

Place of Work: Duesseldorf

Role: Software Developer (ASP.Net) 

Customer: Chronocycle Solutions GmbH


Tasks:

  • With a team of 6 developers we built a web-based ERP software for the insurance sector
  • Besides the integration of finance-related interfaces and data imports like MT940 and DTAUS, I was responsible for performance optimizations, for both frontend and backend, particularly the Microsoft SQL Server database


2005 - 2007

Place of Work: Cologne

Role: Web Developer Marketplace 

Customer: Sedo GmbH


Tasks:

  • I was a member of the web application development team and amongst other things responsible for the development of the real-time auction system and several backend tools


1998 - 2005

Place of Work: Cologne

Role: Software Developer 

Customer: LECTOR Computersysteme GmbH

Branchen

Branchen

In addition to my technical skills, I have engaged directly with lawyers during recent years on compliance issues and European regulation within the blockchain and financial sectors, emphasizing my comprehensive understanding of this industry's legal framework and processes in the environment of Banking and Insurance.


Furthermore, I am familiar with processes and legal aspects in eCommerce and GDPR. I am still not a lawyer, but I talked to them a lot to understand the important things.

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