Alec Watts focused on backend stability for TanStack/db, addressing a complex bug in the live query subsystem. He resolved issues where live queries failed after collection garbage collection by implementing a cache reset mechanism that clears graph, inputs, pipeline, and collectionWhereClauses caches when subscriptions are unsubscribed and collections are garbage collected. This approach ensures that a fresh D2 graph is compiled for each new live query execution, preventing reuse of finalized graphs and reducing runtime failures. Working primarily with TypeScript and leveraging his skills in backend development and database management, Alec demonstrated depth in debugging and GC-aware cache lifecycle management.