I bet my career on AI in 2015. It took a while.
I built Stepsize, raised $10M, and sold it to ClickUp. There I shipped Ask AI and the @Brain agent to millions of people. I also build on my own, and write down what happens while it's still messy.
Born in Paris, moved to London to join my brother Nick and chase the startup dream. Most of what I know I learned by shipping things and watching them break.
The bet
In 2015, four of us sat in a London flat and trained a recurrent neural network to write code. It was terrible. The output barely compiled. We quit our jobs anyway.
My brother Nick, our friends Jared and Matt, and me. What we saw in that broken prototype was the whole thing: one day you would describe what you wanted and software would build it. People thought we were nuts. We moved into the chef's quarters of Jared's parents' Chinese restaurant in Hastings and started Stepsize.
The vision was right and the plan was wrong. We assumed AI would need our proprietary data to understand a codebase. Turns out attention is all you need. Being certain about where things are going has been worth far more to me than being right about how they get there.
Selected work
Stepsize AI
Editor-first issue tracker and AI-powered updates for software teams
An issue tracker that lived inside the code editor, plus AI status updates that told a team what it had actually shipped. Four of us started it above a Chinese restaurant in Hastings and finished it as a company of fifteen.
Ask AI & @Brain
The AI system inside ClickUp's everything app
Two products inside ClickUp's AI system: Ask AI, the assistant built into the platform, which we rebuilt until positive ratings roughly doubled, and @Brain, an agent you mention like a teammate, built on RAG and 35+ tools.
Clien.ai
Stress-test your startup ideas before you build them
Describe an idea and a research agent stress-tests it: personas, simulated interviews built to push back rather than agree, competitor sweeps, forum mining. Twenty to thirty minutes, two or three dollars.
Lessons from Lenny
Interactive AI skills for PMs and founders, distilled from 269 episodes of Lenny's Podcast
Lenny Rachitsky open-sourced 269 podcast transcripts, so I turned the frameworks inside them into ten Claude Code skills you can actually run.
03 — The letter
Watch me build it, mistakes included
Full Stack Founder is a weekly note on shipping products with AI as a team of one. Free, and you can leave whenever.
Already convinced?Subscribe on Substack- 01What I shipped, and what it actually took.
- 02The tools and workflows earning their keep right now.
- 03Where I got stuck, and the things that failed.