Every job post now says "we expect you to use AI in your daily workflow." Good — because used well, an AI coding agent is a real multiplier. Used badly, it's a confident intern that ships bugs. After months of building and shipping merged open-source PRs with an agent in the loop, here's what actually changed — and what didn't. What genuinely got faster Navigating unfamiliar codebases. Dropping into a repo I've never seen and asking "where is X handled and why" collapses hours ...