Replit

Agent 4, Replit's current generation, runs tasks in parallel rather than sequentially — so authentication, database setup, and UI work happen at the same time instead of in a queue. The vendor describes a model where you submit requests in any order and the agent sequences them intelligently, which means a non-technical PM can iterate on a live app the way an engineering team would sprint on it. That promise holds well for greenfield apps, internal tools, and MVPs that live inside Replit's own infrastructure. The ceiling appears when you need to export the underlying code to your own hosting stack, integrate with services the platform's 100+ connectors don't cover, or take fine-grained control over architecture decisions the agent has already made on your behalf.