Stories from real builds.
What shipped, what broke, and how AI is changing the way software gets made.
10,600 Trajectories: Mutation Testing in a Video Game
A harness flies each Kepler mission thousands of times with randomised inputs, then searches for the cheapest solution. It answers whether the puzzle has a solution at all — and it is what agentic engineering actually looks like: not generation, search.
Build log
8 Sep
Engineering × Art
The frontier models are all good enough that the tool stopped being the advantage, and what is left is the craft of combining them — which is the part nobody can buy in a launch.
Commentary
7 Sep
Where Specs Work and Where They Don't
Four properties decide whether the full verification pattern belongs: deterministic, calculable, enumerable, objective. Most of an app fails one.
Research
4 Apr
Bugs Are Missing Scenarios
In spec-driven development the code isn't wrong — it was never told what to do for that combination. The fix is always the same: add the scenario.
Research
3 Apr
Humans Think in Dimensions, Not Test Cases
Ask a shop owner how time tracking works and you get dimensions, not test cases. The combinations fall out of the dimensions mathematically.
Research
2 Apr
Agentic Engineering Is Pattern Engineering
The value of working with AI agents isn't faster code. It's building verification patterns the agent operates within, so correctness is structural.
Research
1 Apr
The Undocumented iOS Limit That Rewrote My Architecture
I needed two concurrent speech recognition streams. Apple's docs don't mention you can't have them — the second start silently kills the first.
Build log
31 Mar
Designing a Test Runner for AI Agents
Seven stuck Ruby processes, running for hours, holding database connections. The agent that spawned them had moved on, oblivious.
Build log
23 Mar
Git History Is the New Performance Review
Thousands of commits across every project I run, and my decisions were invisible in all of them. The log said AI did the work. That isn't what happened.
Commentary
15 Mar
Structure Over Prompts
Everyone's building AI agents to orchestrate AI agents. I built a state machine instead. Zero orchestration tokens, no hallucinated transitions.
Build log
8 Mar
Software, the New Services
Sequoia says the next trillion-dollar company will sell services, not software. We think it's the reverse — custom software is about to replace the services layer entirely.
Commentary
7 Mar
Grok & Roll #5 — The Software Industry Is About to Explode
The software industry is on the verge of a massive expansion. AI is collapsing the cost of building, and that changes everything. Are you ready?
Note
27 Feb