R1: 1. Experience: Explain a system you built or worked on in current orgainisation, production issue faced, how to scale up. 2. Backend: Microservices used in your system, Rate limiting implementation, Health checks / monitoring, Node Event Loop explanation, What happens if process.nextTick is used heavily, Graceful shutdown in Node.js, Memory leak detection, process.exit usage. 3. DSA: Explain a non-linear data structure, Tree traversal problem (Inorder traversal) R2: - In-Depth Questions on the latest feature worked on the current organisation, how it works, scaling etc. (Have mentioned File processing - so questions based on the architecture, performance, scaling, enhancement, monitoring etc.) - Questions related to API Performance, how to increase performance, handling bulk response, security etc.