System Design Decisions

Architecture decisions for common system design components. Each page documents real constraints, trade-offs, and failure modes.

Topics

Cache invalidation strategies, TTL decisions, cache-aside vs write-through, and compliance considerations.

Queue selection, retry strategies, DLQ design, idempotency, and ordering guarantees.

Partition key selection, hotspot mitigation, rebalancing strategies, and cross-partition queries.

Algorithm selection, fairness considerations, dependency protection, and abuse prevention.

CAP trade-offs, eventual consistency, conflict resolution, and multi-region strategies.

See also: System Design (Legacy) for additional HLD and LLD examples.