TL;DR of
@leerob's 45-min Stanford lecture on always-on agents, the last 10 minutes especially:
Build as little UI as possible, because you'll rebuild it every six months. Every app either goes agentic or becomes "a headless piece of data for another agent."
My takeaway: the UI becomes the least important part of a personal agent.
What matters is the stuff you can't see: memory, agents learning on the job, knowing when to speak up and when to stay quiet.
You don't feel any of it on day one. You feel it on day ninety.