Agentic Coding Harnesses at Prime Video
Agents that write and review production code for a page millions of customers use
- millions customers on the page I ship to
- write + review code changes handled end to end
- laptop-free long-lived remote agent sessions
I’m a Software Development Engineer on the Prime Video Detail Page team. It’s the page millions of customers land on before they press play, and I ship customer-facing features for it to production. AI coding agents are the default way I work, and I’ve automated as much of that work as I can.
Why build my own harness
General-purpose agents don’t know how a particular team works: its review conventions, how changes are staged and what a reviewer will send back. So I built custom harnesses around my team’s development process. They take a code change from writing through to review, and they follow the same steps a teammate would.
Where the human stays
The agents write and review changes end to end, and I keep two jobs: steering and final sign-off. The code goes to production in front of millions of customers, so nothing ships on an agent’s say-so alone. Keeping sign-off is the trade I chose, because it saves most of the typing without giving up any of the accountability.
Running without me
The agents run as long-lived sessions on a remote cloud desktop, with persistent access and automated workflows. Work keeps moving when my laptop is closed, and I spend my time on product decisions rather than keystrokes.
Internal Amazon work, so no repository or screenshots. Happy to talk through how the harnesses are structured.