Cheat Sheet
| Question | Core Idea | Senior Signal |
|---|---|---|
| Q216 | App Router | Keep data and secrets server-side; pass small typed serializable props into client islands. |
| Q217 | Typed telemetry | Standardize Web Vitals and analytics events with route, release, metric, and privacy context. |
| Q218 | Flags | Type flag names and variants, validate remote config, and require owners plus cleanup. |
| Q219-Q220 | Testing and delivery | Use TypeScript as one quality layer alongside runtime tests, budgets, and rollout monitoring. |