Blog — 2024 to 2026
Every project, written up.
One post per project, each with a working demo on sample data where there is one, plus looks back on competitions, trips, volunteering and startup work. Every post is dated close to the event and says when it was written.
- posts
- 41
- years covered
- 4
- hackathons
- 5
- minutes of reading
- 104
The main projects
Start here
Kobe: what I actually built as founding engineer
The Launchpad series tells the three weeks from the inside. This post explains the product: an agent that finds the best path to a person through your own network, and my part in it.
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Eight months at MitJulia: what you learn when an AI answers the phone for hair salons Since January I've been working on Julia, the AI receptionist by MitJulia (formerly Friseurtelefon). A progress report with numbers. -
Launchpad, part 5: Demo day A pitch to investors, the result as announced to the teams, and two weeks in Pennsylvania as date lines. -
PneuNet: eighteen months of chest X-rays, three competition rounds How a school research project on pneumonia detection made it to the national final of Jugend forscht, and why the DICOM viewer is the real product in the end. -
An agentic system with BMW: the code calculates, the model explains In the seminar Building Agentic Products we're working with BMW on a system that spots early warning signs of unplanned machine stops. An interim update, as abstract as confidentiality requires. -
ESN Event Hub: six tools, one event and why we built it boring For the Erasmus Student Network in Potsdam we mapped the event process, modelled it and shipped a small web app as a team. Understand first, then build.
All posts
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Launchpad, part 4: Revenue, not points Week two: an elimination that turned into a revenue ranking, a pitch round down to five teams, and people giving away their day off. Looking back, written the evening before demo day. Part 4 of 5 of the Launchpad series. -
Launchpad, part 3: Ten interviews, completely useless Through the first elimination, users who look past the bugs, and the sentence that took my engineering reflex apart. Looking back, written at the end of our first week at camp. Part 3 of 5 of the Launchpad series. -
Launchpad, part 2: "Your system has run out of application memory" New York, a bus from Times Square, a camp in the woods and two nights in which first the laptops and then we hit our limits. Looking back, written on the morning of the first elimination day. Part 2 of 5 of the Launchpad series. -
Launchpad, part 1: Seven days before A call from René, twenty minutes to decide, Tenerife cancelled and one week of building before the flight to New York. Looking back, written on the day we flew to New York. Part 1 of 5 of the Launchpad series. -
Voya: 48 hours, more than 50 worktrees, no prize At the OpenAI hackathon at IdeaLab! in Vallendar I coordinated parallel AI coding agents. We didn't win, but the MVP is live. Looking back, written the day after the hackathon. -
MediaSync: photos from your phone to a USB stick, no cloud For half a year I built an Android app on the side that backs up photos and videos straight to a USB stick. About 26,000 lines of Kotlin, on my own. Looking back, dated to the day of the last commit. -
A website for takeøff in five days, with a night sky and no tracking Our cultural collective in Potsdam needed a website. I built it in five days, bilingual, with my own Canvas scene engine and a data layer that can take a database later. Looking back, dated two days after the last commit. -
Organising startup tours: Munich, Amsterdam and zero replies Since February I've been organising startup tours at HPI Engine. What worked in Munich and what Amsterdam taught me about cold outreach. Looking back, written after the feedback meeting on both tours. -
¡Vamos!: a Spanish app in two days, offline and without an account My school Spanish is B1 and getting rusty. So I built myself a small learning app that runs in the browser, works offline and doesn't ask you to sign up. Looking back, dated two days after the last commit. -
Project Midas: a fund that looks too good, and three mistakes inside it For a seminar on statistical fallacies I built a synthetic trading dataset with three hidden biases. Plus a talk on hallucination in language models. Looking back, dated to the end of the summer term. The grade is added as a note at the end. -
PowerSqueak: seven-year-old code, nine sprints and a bug in the event routing In the Software Engineering course we took over an old presentation tool written in Smalltalk and kept building it. My features: slide sections and a presentation timer. Looking back, dated three days after the code defense. The grade is added as a note at the end. -
A school day for 87 eleventh-graders, and how it got there As an sdw scholar I led the school outreach for our regional group's social day. On July 1 it happened. Looking back, written two days after the school day. -
AWS World Sports Innovation Cup: research first, then build, then Frankfurt We won the AWS World Sports Innovation Cup 2026 with the Connected Arena challenge, and I pitched in the final. Looking back, written a few days after the final at the DFB campus. -
Five people, one trip to Sicily and a planning tool in twelve days Instead of a spreadsheet and three group chats I built our travel group a small planning site with votes, a budget and a day plan. Looking back, dated two days after the last commit. -
START Hack in St. Gallen: no prize, a good prototype Straight from the road trip to START Hack: 36 hours on an AI-guided thesis journey for Studyond. Looking back, written the day after the trip home from St. Gallen. -
Arctic Sprint, part 3: Lovable, Soundboks and back in Berlin at 4 am Two office visits, one product decision, and 17 days that end with cleaning a van. Looking back, written the day after we got home. -
Arctic Sprint, part 2: Arctic Circle, northern lights, Lofoten in a storm Why we skipped the North Cape and what we got instead. Looking back, written on the way south from the Lofoten islands. -
Arctic Sprint, part 1: by van from Berlin to Helsinki Exams done, a van from the startup, a laptop on the passenger seat: week one of our travel-and-code road trip. Looking back, written on the way north out of Helsinki. -
Red Cross medic in civil protection, next to a full semester I've volunteered with the German Red Cross in Potsdam since October 2024. This winter it was a major fire and black ice. Looking back, written in late February 2026 after the black ice deployment. -
800 runs of dig: what one semester of internet measurement taught me In the English-language course Introduction to Internet Measurements I designed, ran and analysed a measurement every week. The last one was my own RIPE Atlas study. Looking back, dated to the end of the term, just before the road trip. -
Scholar of the sdw: how I got in, and what the first semester looked like Since October 2025 I am funded by the Klaus Murmann Fellowship of the Foundation of German Business. Notes on the application, the admission weekend in Berlin and the regional group. Looking back, dated two days after the admission weekend in Berlin. -
TouchdownTactics: seven people, one game in Smalltalk, and I had the cards In the Software Architecture course a team of seven built a real-time strategy game in Squeak/Smalltalk. My part: hand, cards and elixir. Looking back, dated two days after the hand-in. The grade is added as a note at the end. -
ReThink Recycling: live trash detection without a GPU At the Siemens × AWS hackathon in Berlin I built real-time trash detection, and our team took first place. Looking back, written a few days after the hackathon. -
Bundesliga Hackathon: three days, 71 commits, one of the winning teams Building a chatbot app for the Bundesliga with Hasso's Kickers at the first Bundesliga Hackathon by DFL, AWS and EintrachtTech. Looking back, written a few days after the final in Frankfurt. -
A scholarship from home: Sparkassenstiftung Erfurt The foundation of my home town's savings bank supports my pneumonia detection project for a year. What it is for, and what I spend it on. Looking back, dated to the start of the funding year. -
OweFlow: 120 commits, then the question about money A fellow student and I spent a month building a Flutter app that splits group expenses. What stopped us wasn't the code but payment regulation. Looking back, dated a few days after the last commit. -
Ratard: from a one-minute pitch to a browser extension in a week We won Best Pitch at HPI Engine's E-Challenge with an idea against fake news. A week later I started building it. Looking back, dated to the end of the prototype week. -
First week at HPI: why I picked the small one 80 places a year, a selection process with an aptitude test, and a decision against some big names. Looking back, written in my first week of lectures. -
A business model in one week: JugendUnternimmt Summer School A special prize from Jugend forscht sent me to a founders' workshop week in Erfurt. Our team took first place in the pitch competition at the end. Looking back, dated two days after the summer school. -
Karate since childhood and a national championship before my school certificate Seventh place at the German championships in my hometown, six days before my Abitur certificate. Looking back, written the day after the German championships in Erfurt. -
335 points: what the MINT-EC certificate actually counts With my Abitur I received the MINT-EC certificate with distinction. It is less an award than a ledger of my school years: competitions, camps and extra lessons. Looking back, dated the day after the certificate. -
Bundeswettbewerb Informatik: two first prizes in round one, and a weekend at HPI Three years of Germany's Federal Computer Science Competition: what the homework round asks for, what I got out of it, and how a camp in Potsdam became my first contact with HPI. Looking back, dated the day after the camp at HPI. -
Three of us, one day in Jena: the computer science team competition Our team of three from Erfurt won the computer science team competition of Thuringia's specialised STEM schools. A short note, because I only write down what I can back up. Looking back, dated two days after the competition. -
GorillaScout: getting into a pipeline that four cohorts built before us Since October I've been in the bachelor's project that re-identifies wild gorillas in camera-trap video. An interim update on how you get into a pipeline that four cohorts built before you. Interim update, written in the project's first month. -
Deep learning without the exam: why I rebuilt the course book as a website This term I'm sitting in on the Deep Learning lecture at HPI. To really understand the material, I rewrote the first part of the course book as a simplified German study site with interactive demos. Interim update, written during the term.
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