bi-16 — Broader Ideas
What survives
Chromium paths rot; two are already documented as stale in this book. The eight patterns do not, because they are properties of the problem:
- Author-supplied guarantees unlock impossible optimisations.
- Record cheaply, resolve precisely, once per frame.
- Immutability is the enabling condition for caching.
- Incomplete cache keys fail silently.
- Author code must never observe a half-built state.
- Speculation is safe only when unobservable.
- Restrictions make circular systems analysable.
- Organisational boundaries become architectural boundaries.
These are the exportable output of the whole curriculum. Each was found independently in both a C++ rendering engine and a JavaScript runtime, which is the evidence that they are not idioms of either.
Where to go next
| Direction | Next step |
|---|---|
| Depth in Chromium | pick one subsystem and go to contribution rung 4–5 |
| Breadth in the platform | WPT contributions in areas you studied |
| Framework authorship | take fw-04's runtime to SSR and hydration |
| Organisational impact | write your team's cold-read procedure and cost model |
| Cross-track | fe-* capstones — architecture and organisational judgement |
The honest completion criterion
The mastery list includes an upstream-quality Chromium change. If the toolchain blocked it, record that explicitly rather than quietly dropping it.
A curriculum that lets you mark yourself complete without the falsifiable step is a curriculum that flatters you — and the entire method here has been to prefer measurement over flattery.