Systems Architecture & Distributed Systems Topics
Large-scale distributed system design, service architecture, microservices patterns, global distribution strategies, scalability, and fault tolerance at the service/application layer. Covers microservices decomposition, caching strategies, API design, eventual consistency, multi-region systems, and architectural resilience patterns. Excludes storage and database optimization (see Database Engineering & Data Systems), data pipeline infrastructure (see Data Engineering & Analytics Infrastructure), and infrastructure platform design (see Cloud & Infrastructure).
Multi-Tenancy and Isolation
Serving many tenants from shared infrastructure: tenancy models (silo, pool, bridge), data isolation, per-tenant data residency, noisy-neighbor mitigation, per-tenant limits, and security boundaries between tenants. Covers the cost, isolation, and blast-radius tradeoffs of shared versus dedicated resources, and business continuity: per-tenant backup, disaster recovery, and compliant tenant offboarding and deletion. The architecture layer specific to SaaS and platform products.
API and Interface Design for Distributed Services
Designing the contracts between services and clients: REST, gRPC, and GraphQL tradeoffs, versioning and backward compatibility, pagination, rate limiting, and idempotent endpoints. Covers request/response modeling, error contracts, and API gateway responsibilities. Focuses on the interface layer that ties distributed components together, not internal data schemas.
Distributed Systems Security and Trust
Security problems that exist because a system is distributed: keeping trust state correct while it propagates across many services, clusters and regions. Covers credential, token and certificate revocation under eventual consistency and network partitions; fleet-wide rotation of signing keys, secrets and trust anchors without outages (key rollover and grace windows, canary rotation, recovery from a compromised root); distributed authorization (replicated policy decision points, cached decisions, fail-open versus fail-closed when an auth dependency degrades); propagating caller identity and permissions through service call chains; tamper-evident audit trails across services and regions (hash chains, Merkle proofs, ordering events with imperfect clocks); Byzantine and partially trusted participants; cross-cluster and cross-organization trust federation; securing shared distributed components such as caches and message brokers against injection, replay and cross-tenant access; protecting data in transit across region boundaries; and tenant isolation as a security blast-radius boundary. Steady-state mTLS, service-mesh identity and network segmentation mechanics are covered by zero-trust service-to-service security; single-system cryptography and KMS basics by applied cryptography.