Hiring and firing a DBA

Hiring our DBA For the past sixty days, Buttondown 1I take liberties here and throughout the essay: this was all Matias' doing. He also wrote a great piece on our migration to Planetscale, and also cites Planetscale's recommendation for this experiment. ran a scheduled LLM invocation once a day. Every morning it would look at the previous few days of database load in PlanetScale, and — if, and only if, it was sufficiently confident — it would open a pull request containing exactly one performance improvement to the seam between our app and our database. I think of this as a longitudinal study, and a fairly cheap one: LLMs are extremely well suited to performance optimizations, precisely because such optimizations can be evaluated and then trivially discarded. 2We used GPT 5.3 Codex High for this, but I suspect our outcomes would have been broadly similar with whatever model we reached for. Two months down, and here's where we're at: We decreased our overall database reads by 25% for…