Independent Software Engineer

Freelance • 2018 — current

I worked as independent Software Engineer with various teams, e.g.:

  • Financial Service Institution: Development of internal APIs for a Bitcoin/crypto-currency custody service and developer tools to allow efficient development of crypto currency products.
  • Investment Fund (Africa): Performed technical due diligence on early stage investments and specified technical investment thesis.

KI decentralized GmbH

Sr. Blockchain Expert • 2017 — 2018

I advised KI decentralized customers with their Blockchain and Smart Contract (Bitcoin/Ethereum) business strategies, facilitated technical trainings and was responsible for the development of innovative blockchain applications.
Companies I worked with: Daimler, LBBW, Lufthansa


Sr. Blockchain Engineer • 2017

Software engineer for the financial services company operating in Ghana and Senegal.
I was responsible for the integration of banking partners and managed the development team. Evaluated and developed different Ethereum blockchain based solutions to rethink the existing savings/loans business model.

Great Lakes Energy Rwanda

Technical Consultant • 2015 — 2016

Technical consultant for Kigali based solar energy solutions provider.
I designed and implemented a centralized solar monitoring system and have been planning a mobile money integrated smart meter solution that enables a pay-per-consumption business model for solar systems in rural Rwanda.

Railslove GmbH

Co-Founder / CTO • 2008 — 2015

Co-founder of Railslove, a software consultancy for sustainable software and innovative web products. Railslove applies a lean and agile approach to turn ideas into applications using modern web technologies. The company had grown to ~20 employees in 2015.

During my time at Railslove I worked with a wide range of clients from different sectors and sizes. Some of the recent projects:

  • SEPAone — Team lead and software architect of the SEPA direct debit payment solution. I directed the team designing and implementing the APIs as well as the EBICS (Electronic Banking Internet Communication Standard) integration to German and European banks.
    Responsibilities: project management, software architecture, customer integration support
  • Skrill — Technical consultant to the business and product development teams at Skrill. I led the development teams for the merchant facing management tools and developer APIs of Skrill's PSP (Payment Service Provider) product. I coordinated and planned the product development and consulted Skrill on strategic product decisions.
    Responsibilities: software architecture, product management, team lead
  • BitPesa — Technical consultant in charge of the launch of the Bitcoin to mobile money (m-pesa) remittance solution for East Africa. I led technical negotiations with potential banking and integration partners and consulted BitPesa on the partner selection.
    Responsibilities: software architecture, project management, budget planning, partner management

Hackers & Thinkers UG

Partner • 2013 — Present

Founding partner of the holding company hackers & thinkers UG. Its latest venture is hack.institute which is organizing innovation events and workshops connecting the IT community and corporates.


2006 — 2007

Part of the founding team and in charge of the product development of DaWanda, the marketplace for handmade products in Europe.


Hochschule Bonn-Rhein-Sieg

Bachelor of Science in Business Information Systems • 2007 — 2009

Combination of computer science and business administration;
Focus: Business Process Management

Hochschule Heilbronn

Electronic Business • 2004 — 2006

Skills & Technologies

I mostly care about using the right tool for the job and processes to efficiently collaborate as a team. That said here is a list of technolgies/areas that I am most familiar with and have been using extensively:

  • Ruby (on Rails)
  • JavaScript
  • Solidity
  • Go
  • Python
  • PostgreSQL / MySQL
  • MongoDB
  • Redis
  • RabbitMQ / MQTT
  • Docker & Kubernetes
  • DevOps
  • Agile
  • Lean
  • Scrum
  • Kanban
  • Product dev
  • Bitcoin
  • Ethereum
  • Blockchain
  • FinTech

Special Projects

Kosmos Kredits

Kredits is a Ethereum based framework to build programmable organizations. It is using Smart Contracts to create an organizational structure for Open Source projects and open organizations.

Bitcoin, Ethereum, Blockchain

My current focus is on new technology for the decentralized web and its effect on future, decentralized business models. I am doing independent work on Smart Contracts, Decentralized Autonomous Organizations, Online Payments and related topics.

Some of my thoughts and experiments are documented on my GitHub repositories and my blog.

Community Work


Co-organizer of the AfricaHackTrip and related initiatives to explore and foster collaboration with innovation hubs in East-Africa.

Conferences & Meetups

Co-organizer of a broad range of local and international conferences and meetups (i.e. DevHouse, Nodecamp.eu, Ruby/JS meetups, Kigali Online Payments meetup).

Coworking-Cologne / Coworking.de

Co-founder of Coworking-Cologne which was the first coworking space in Cologne, Germany. As hub for many events and organizations, the not-for-profit cooperative supports the local tech community and fosters interdisciplinary collaboration. The cooperative also founded the German coworking network coworking.de and the region's first fab lab - Dingfabrik - was initiated by this community.