GrowthBook
text published 2026-03-26 · Open on LinkedIn ↗
Unit tests have one job: tell you if something is broken. AI apps just made that job impossible. When your application is non-deterministic, there's no pass or fail. There's only better or worse. And the only way to know which one you're looking at is to test with real users and measure what actually happens. @marcocasalaina, VP of Products at Microsoft, puts it plainly: major in evals, set acceptable error rates by use case, and A/B test your models and strategies. Because what "good" looked like a few months ago is already outdated. Experimentation isn't a nice-to-have for AI apps. It's the only measurement tool that still works. Full episode in the comments. #experimentation #abtesting #AI
Engagement over time
Only one snapshot so far — the engagement-over-time curve appears once the daily scrape has captured this post at least twice.