CQRS (Command Query Responsibility Segregation)
Design a CQRS-based backend that scales read and write workloads independently using a transactional command model and asynchronously updated read models. Covers event/CDC pipelines, projection correctness, caching, and consistency trade-offs at high scale.
Horizontal Scaling Blueprint (Multi-Tenant Activity Feed)
Design a horizontally scalable architecture by making compute stateless, partitioning stateful stores, and decoupling workloads with queues/streams. Focuses on hot partitions, fanout, caching, and consistency trade-offs while targeting low latency and 99.99% availability.
Event Sourcing
Storing application state as a sequence of immutable events for auditability and rebuilding state