Scalability and Growth Considerations Questions

Understanding how software product and architecture choices behave as user base and data volume grow, and knowing when to evolve from simple implementations to more scalable approaches. Candidates should be able to discuss when to move from in-memory caches to persistent storage, how to implement pagination and incremental data loading, batching and request coalescing to reduce network overhead, and cache invalidation strategies. Cover how application design interacts with scaling concerns such as rate limiting, data modeling, and API versioning, plus operational considerations including monitoring, instrumentation, and cost implications for storage and bandwidth. Also cover safe migration strategies for evolving schemas, handling large queues of pending or offline operations during synchronization, and graceful degradation patterns under heavy load.