Current projects

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  Wishlephant

  Shortly before our kid was born we had the problem that lots of people asked us what we could need as baby shower presents. We tried to organize it using email and an Excel sheet and quickly realized that this didn't scale. After looking into tons of websites that offer a gift registry, I realized none had what I wanted or looked really dated. Together with my wife I build a page that was perfect for us. Wishlephant.com currently has around 50,000 unique visitors during christmas months.

  • Elixir
  • Stimulus.js
  • Postgres
• 

  Bookpile

  I love books and I love independent bookshops. When I wanted to share a book with a friend I had no good way to point them to a place to get it. Bookpile.org solves that: enter an ISBN and it shows you nearby independent bookshops, libraries, and book-tracking sites where you can find it. It deliberately highlights small, independent bookstores over large chains. No affiliate links, no cookies, no tracking - just books and the places that sell or lend them. The code is open source and can be found on Codeberg.

  • Elixir
  • Phoenix
  • Postgres
• 

  Papi Berlin

  Papi Berlin is a Berlin-based community for active fathers*, dedicated to redefining fatherhood beyond traditional gender roles. The group promotes concepts like mental load awareness and needs-oriented parenting. It offers a supportive network through an active Slack channel, where fathers can exchange ideas, seek advice, and share resources on topics such as parental leave, daycare, and parenting challenges. The platform also features blog posts covering family life, educational transitions, and media recommendations. Papi Berlin welcomes all individuals in fathering roles, fostering inclusivity and encouraging participation in its community initiatives. ​

  • Parenting
  • Dads
• 

  SignDict

  SignDict.org is one of the leading dictionaries for the German Sign language. 95,000 unique users per month use the site to learn this wonderful language. I build this site as part of the first batch of the Prototype Fund and continue to maintain it. The code can be found on GitHub.

  • Elixir
  • Vue.js
  • Postgres
  • Redis
  • FFmpeg
• 

  Hier Baut Berlin

  With Hier Baut Berlin I was part of the 9th round of the Prototype fund. My goal was to create a tool to inform citizens of Berlin about changes in their neighborhood. For example, street construction, new bike paths, information about ways to participate in key decisions in the neighborhood.

  This information was available, but scattered on 20-30 pages. With the help of this project you now finally see all important information on one map. It is also be possible to subscribe to changes via email. Never miss an important update anymore.

  The code can be found on GitHub.

  • Elixir
  • Stimulus.js
  • Postgres
  • Pd3f

I also maintain a couple of smaller open-source libraries and tools. Check out my Codeberg and GitHub profiles for a complete list.

Past projects

In over 20 years of working in the tech industry, I participated in numerous projects. Here is a small list of things I am proud of.

• 

  Airy

  From 2018 till 2021 I was freelancing for Airy as part of their React.JS frontend team. Airy is an open-source conversational platform to power conversations with an open source Website Live Chat, Messengers like Facebook Messenger, WhatsApp and more.

  The code can be found on GitHub.

  • TypeScript
  • React
• 

  Sloth Emoji

  An emoji? Yes! Did you know that you can write a proposal for Emojis? I got lucky and my proposal for the sloth emoji was accepted and now the sloth can be found on every phone and laptop 🎉.

  I hopefully made the world a better place with adding the 🦥 emoji. Also want to create an emoji? Join the emojination slack, and they will help you make it happen.

• 

  bitcrowd

  For a couple of years I was a co-owner of bitcrowd, a berlin based web agency. During my time there we helped many startups to be successful businesses. We build the first code for startups like time:matters, Liefery, Krautreporter and many more.

  • Ruby on Rails
  • Angular
  • React
  • Postgres
  • Redis
• 

  putpat

  From 2009 till 2013 I was part of putpat.tv. Putpat tried to re-invent music television for the modern internet age. With over 50,000 videos and a smart algorithm to create channels based on your taste profile it was loved by a huge user base. Since it was a relative small team of developers, I was responsible for many client applications. Starting with software that ran on TVs to more classical Android and iOS apps. Besides that, I build parts of the ingestion and tagging platform.

  • Ruby on Rails
  • JavaScript
  • Objective-C
  • Java
  • Postgres
  • Redis
  • FFmpeg
• 

  TV-Browser

  TV-Browser is a Swing based open-source desktop TV guide for more than 1,000 TV stations. I was the lead developer till 2011 and in its peak it had over 150,000 active users. The code can be found on SourceForge.

  • Java
  • Swing