Build smooth UIKit lists and collections

Use when designing, implementing, reviewing, diagnosing, profiling, or regression-testing performance-sensitive UIKit lists and collections built with UITableView or UICollectionView. Apply to diffable data sources, compositional or custom layouts, cell and supplementary registrations, reuse and configuration state, self-sizing, prefetching, asynchronous images, UIHostingConfiguration cells, batch updates, scrolling hitches, main-thread work, and memory-aware caches. Trigger for requests to fix stuttering scroll, stale reused content, expensive cell preparation or layout, snapshot churn, image-decoding hitches, or collection memory growth. Do not use as the lead for an ap…