Simon's comment about mental exhaustion resonated with me. Earlier this year I spent ~3 days generating 11k lines of HTML validation and sanitization code using multiple agents (having them cross-check each other's work because it was security-sensitive). By the end of those days I was completely wiped out. One night I slept 10 hours just from the mental fatigue. I was surprised that it was just so exhausting! I barely wrote any code myself; I was essentially doing code reviews and exercising architectural judgment all day. I've been thinking a lot lately about how AI changes the cognitive load of software development, not just the speed of it.
I've also noticed the pattern amplification effect he mentioned. Agents mirror whatever quality level already exists in the codebase. In clean, readable areas they reinforce good structure. In messy areas they reproduce the mess just as faithfully. If anything, AI seems to make codebase hygiene even more important, not less. It'll be interesting to see how codebase hygiene affects companies' ability to implement AI harnessing and other advanced techniques.
