Notes from the work, written close to the event.
Each post looks back on one moment: a hackathon, a week at a startup competition, a duty shift. Dated the day it was written, so nothing is rewritten with hindsight.
Launchpad, in five parts
Two weeks at a startup competition in Pennsylvania with Kobe AI, from the call a week before to demo day.
2026
- · 2 min read
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. - · 3 min read
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.
Interim update, written shortly after the first interim review. - · 3 min read
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. - · 4 min read
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.
Looking back, written a few days after my last Kobe commit. - · 3 min read
Launchpad, part 5: Demo day
A pitch to investors, the result as announced to the teams, and two weeks in Pennsylvania as date lines.
Looking back, written the day after demo day. Part 5 of 5 of the Launchpad series.
- · 3 min read
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. - · 3 min read
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.
- · 3 min read
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.
- · 3 min read
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.
- · 2 min read
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. - · 3 min read
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. - · 3 min read
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. - · 3 min read
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.
Looking back, written after closing the timeout and alerting tickets in early September. - · 3 min read
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.
- · 3 min read
¡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. - · 3 min read
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. - · 3 min read
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. - · 3 min read
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.
Looking back, dated three days after the final presentation. The grade is added as a note at the end. - · 2 min read
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. - · 2 min read
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. - · 2 min read
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. - · 2 min read
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. - · 2 min read
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.
- · 2 min read
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.
- · 2 min read
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.
- · 2 min read
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.
- · 3 min read
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. - · 3 min read
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.
2025
- · 2 min read
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. - · 3 min read
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. - · 3 min read
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.
2024
- · 3 min read
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. - · 2 min read
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. - · 2 min read
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. - · 3 min read
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.
Looking back, written a few days after the national final in Heilbronn.