Browser and dom Javascript Questions

Use event delegation to reduce listeners, support dynamic elements, and improve performance with advanced patterns.

Build a lightweight lazy-loading system that defers image downloads until images approach the viewport.

Implement a robust deep-clone that handles Dates, RegExps, and circular references, and know the tradeoffs.

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

Move CPU-heavy tasks off the main thread with Web Workers, error handling, transferable objects, and fallback strategies.