1. Is javascript single threaded or multi threaded. 2. Concurrency and Parallel (Ref Link) 3. Event Loop (Ref Link) 4. Event Queue, Event Heap, Event Stack, Browser Web API 5. http1.1, http2, http3 6. How to handle large Database (Ref Link) Answer: Indexing, Partitioning, Replica, Sharding, Caching