> be anthropic engineer > realize long-running agents still have goldfish memory > every new context window = new intern who forgot everything from yesterday > project goes from “build a clone of ChatGPT” to “why is half the frontend missing again?” > agents try to one-shot entire apps > run out of context mid-feature > next session wakes up like “boss… who touched the router folder? why is the server on fire?” > other times claude walks in > sees 3 buttons rendered > declares the whole project complete > packs up its laptop > goes home > humans don’t work like this > engineers leave breadcrumbs > notes, git commits, tests, todo lists > “here’s what I did, here’s what’s next, don’t break the login page again please” > so anthropic builds a harness based on that > two-agent setup: initializer agent, coding agent > initializer agent = the senior dev on day one > sets up: > – _init.sh > – claude-progress.txt > – feature_list.json (200+ features, all marked failing) > – the first git commit > basically: “here’s the blueprint, don’t get cute” > coding agent = the worker bee > every session: > – read the progress > – read the git log > – read the feature list > – pick ONE feature > – implement it > – test it end-to-end as an actual user > – commit code > – leave notes > – do NOT break anything, or revert yourself > incremental progress > chaos > and forcing the agent to act like a real engineer = night and day difference > testing was the big “aha” > claude kept marking features done that absolutely were not done > (“unit tests pass” ≠ “the app works”) > give it browser automation + puppeteer > claude suddenly starts catching bugs it introduced 5 minutes ago > screenshots, clicks, actual user flows > end-to-end or bust > limitations still there > puppeteer can’t show alert modals > claude can’t see everything > vision quirks remain > but it’s way closer to real QA than “lol curl localhost:3000” > typical session now looks like: > “pwd” > read progress > read features > read git log > start server > sanity test > fix broken stuff > choose next feature > implement > test > commit > leave breadcrumbs > repeat > four classic failure modes solved with structure: > – agent declaring victory too early → feature list > – messy environment → git + progress logs > – premature ‘passes’ → real testing > – agent forgot how to run app → _init.sh > does it solve everything? no > still open questions: > single agent vs multi-agent division of labor > maybe future = dedicated QA agent, cleanup agent, test writer agent > maybe research workflows get similar scaffolding > maybe finance models get their own version > but the core insight stands: > long-running agents don’t fail because they’re dumb > they fail because we throw them into multi-session hell > without giving them the engineering rituals humans rely on > give them structure, tools, tests, logs, diffs > they stop acting like goldfish > and start acting like teammates