Scalable System Architecture and Design Principles Questions

Architectural patterns principles and decision making for building systems that are maintainable resilient and able to scale. Coverage includes service decomposition and trade offs between microservice architectures and monoliths; layered and n tier architecture patterns; event driven design and command query responsibility segregation pattern; choosing synchronous versus asynchronous communication and its impact on correctness and latency; design principles such as loose coupling high cohesion separation of concerns and single responsibility; state management and session handling and when to favor stateless designs; application programming interface design versioning and contract management; front end and user experience considerations such as resource loading and progressive rendering; migration strategies for evolving systems and incremental refactoring; and how to weigh latency throughput reliability cost and development velocity when selecting architectures. Candidates should illustrate pattern selection with concrete examples and justify operational and developer experience implications.