Data Modeling and API Design Questions

Evaluate a candidate ability to design clean, extensible data models and service interfaces for complex domains. Topics include modeling entities and relationships, normalization and denormalization trade offs, indexing and query patterns, schema evolution and migrations, backwards compatibility, API contract design for cross team collaboration, pagination and filtering strategies, error handling and idempotency, authentication considerations, and documenting contracts. Candidates should be able to balance performance, maintainability, and operational complexity while enabling future evolution.