Solution: Refactored Comment Viewer App
Stabilize identities in App, make React.memo effective in CommentList, fix selector behavior in StatsPanel, and memoize heavy analytics so the Comment Viewer becomes responsive under React 19.
Refactored comment viewer app
The value of this exercise lies in seeing how small fixes combine to form a clearer mental model of React 19’s rendering and performance behavior. This solution walks through the final refactor, tying each change back to the symptoms observed in the broken version.