Mobile Networking and API Integration Questions

Covers the design and implementation of network communication between mobile clients and backend services. Core protocol knowledge including Hypertext Transfer Protocol and secure Hypertext Transfer Protocol, representational state transfer principles, request and response serialization such as JavaScript Object Notation and protocol buffers, and API patterns suitable for mobile consumption. Platform specific implementation details including Apple iOS networking stacks and libraries such as URLSession, Android libraries such as OkHttp and Retrofit, and cross platform considerations. Reliability and resilience topics including network connectivity change handling, connection pooling, retry strategies and exponential backoff, timeout management, interceptors and middleware, circuit breaker and rate limiting patterns, and error classification and recovery. Performance and efficiency topics including request batching, compression, payload size reduction, caching strategies, cache invalidation, offline first approaches, local data storage and synchronization, conflict resolution strategies, and optimization for bandwidth constrained networks. Security and authentication including Transport Layer Security and certificate pinning, secure sockets layer considerations, token based authentication and refresh flows including Open Authorization and JSON Web Tokens, secure storage of credentials, and certificate and key management. Testing, debugging and observability including network mocking and stubbing, integration testing strategies, logging and telemetry for network flows, monitoring for latency and error rates, and handling of streaming and real time channels such as WebSocket and long polling when applicable.