Cursor + GPT 5-2 built a browser (3M lines of code)

Concurrent agents ran uninterrupted for one week. Each agent had a role: planner, worker, judge. According Cursor blog post GPT 5.2 is better at long-running tasks than Opus 4.5. Adding more management hurts performance, lol. Turns out, scaling agents looks a lot like scaling companies https://x.com/Yuchenj_UW/status/2011863636042469866.