Cheat Sheet
| Question | Core Idea | Senior Signal |
|---|---|---|
| Q171 | Profiler | Measure the slow commit, inspect render causes, change one thing, then re-measure. |
| Q172 | Virtualization | Render the visible window plus overscan, while preserving list semantics. |
| Q173 | Composition | Use compound components and slots when variation would create prop explosion. |
| Q174-Q175 | Boundaries | Portals need accessibility behavior; Server Components need focused client islands. |