work-placementlisted

# Work placement The cheapest work is work you do not do. The next cheapest is work you do once. Almost everything else is a variation on those two sentences. This skill is the entry point for that decision. `davinci:caching` is one rung of it, not the subject. ## 1. The ladder Every piece of work sits on one of four rungs, and it belongs on the highest one its inputs allow: | rung | cost per request | what it fits | |---|---|---| | **build** | none — HTML exists as a file | anything whose inputs change on deploy, not per visitor | | **edge / CDN** | a cache read | identical-for-everyone responses that change on a clock | | **server** | a render, maybe a query | genuinely request-dependent output | | **client** | a download, then work on someone's phone | interaction that cannot be known in advance | A statically rendered route does **no per-request work at all**: the file is on disk, a CDN serves it, and time-to-first-byte is bounded by network latency rather than by anything you wrote. ## 2. Name what forces work downward Work moves down a rung only when something specific forces it. Cookies. Search params. Per-user or per-tenant content. Data that must be fresher than the build. **A route that is dynamic because nobody decided otherwise is the bug.** It is also the most common one, because dynamic is usually the framework default and nothing complains. One request-time value read at the top of a page — a header, a cookie, the current time — can move an entire rout