The paradigm shift is not just from chat to agents, but from episodic agents to persistent AI coworkers: systems that are embedded in daily work and act alongside humans over time rather than being invoked for a task and disappearing.
This changes where product and system boundaries belong. An agentic architecture designed for persistent coworkers needs long-lived state, shared workspace context, interruption/background work handling, and recovery semantics beyond a single request/response loop.
When designing an AI product, decide whether it is a tool that executes on command or a coworker with ongoing presence, context, and ownership over work over time.
AI products are evolving through three distinct phases: chat interfaces (era 1), task-oriented agents (era 2), and persistent AI coworkers (era 3).
Era 3 is persistent AI coworkers who get things done alongside you.