What We Expect

• Backend — Python (FastAPI) and Go microservices at scale. WebSocket and SSE implementation, diagnosing socket-level issues.
• MongoDB at scale — sharding, indexing, replica sets. OAuth 2.0, JWT. Pub/Sub and event-driven architecture.
• Queue management, state persistence, retry and dead-letter handling. Latency, networking, and distributed systems performance.
• Frontend — Next.js. CSR vs SSR trade-offs. Hydration debugging. State management across client and server boundaries. Scalable component architecture. Reverse proxying and build optimization.
• Infrastructure — ECS, CloudWatch, VPCs, load balancers, security groups, DocumentDB, Redis, SigNoz or similar observability tooling. -
• System Design — LLD (design patterns, SOLID, API contracts), HLD (distributed architecture, service decomposition, scalability, fault tolerance), database design (SQL & NoSQL schema modeling, indexing, query optimization, consistency trade-offs).

Nice to have

• AI agent frameworks
• LLM integration patterns (prompt chaining, function calling, structured outputs)
• Firecracker MicroVMs or E2B-style sandboxed execution
• agent memory and long-running task orchestration.