Pull the Cord

The homepage calls a recommendation service inline. That service starts timing out, and because the call is synchronous the whole homepage now takes 8 seconds to render. On-call needs the homepage healthy within a minute. Which mechanism is built for exactly this?

A blue-green cutover to the previous homepage release from before recommendations shipped

A kill switch on the request path that skips the recommendation call and renders a static shelf

A rolling deploy of a patched build that removes the recommendation call from the render path

Autoscaling the recommendation service horizontally so it can absorb the current request volume