The best AI harness is a codebase with a rigorous architecture

Do you know the best AI “harness” everyone is talking about?

A codebase with a rigorous architecture. Simple as that.

Whatever your preferences: pure DDD, TDD, hexagonal architecture, your in-house conventions… What matters is rigour. Maximum rigour.

It is the best way to get an AI let loose in your codebase to follow your way of doing things. Bonus: it is also much faster for you to check afterwards, because you are on familiar ground.

On the other hand, you can pile up all the rules, skills, permissions and CLAUDE.md files you want: if your docs say one thing but the code says 10 others in 10 different places => you shoot yourself in the foot.

The AI will have anything and everything in its context. So it will do anything at all.

Crap in, crap out. That has not changed.

AND FULL CAPS IN PROMPT DRIVEN DEVELOPMENT WON’T CHANGE A THING.