I joined Tabstack four weeks ago. The fastest way I know to understand a product is to build something real with it not tutorials, not toy examples, but an actual app that uses the API under real conditions and breaks in interesting ways.
So I built Rival. Open-source competitive intelligence dashboard that tracks competitor pricing, changelogs, careers, docs, and GitHub signals, diffs what changes, and generates intelligence briefs automatically.
Because they can't accurately report on what they actually do. Memory distorts. Social desirability bias kicks in. Nobody says "I was completely lost for the first 10 minutes" they say "the onboarding was a little confusing at first."