Browser and dom Javascript Questions

Implement a robust deep-clone that handles Dates, RegExps, functions (optionally), and circular references — and know tradeoffs.

Use event delegation to reduce listeners, support dynamic elements, and improve performance — with patterns for delegation exceptions and delegation libraries.

Diagnose memory growth, understand mark-and-sweep, and apply strategies to prevent leaks in web apps and Node services.

Build a lightweight lazy-loading system that defers image downloads until they’re likely to be visible — without IntersectionObserver.

Move CPU-heavy tasks off the main thread with Web Workers and message passing — best practices, fallbacks, and performance considerations.