Architecture
- Domain‑Driven Design (DDD), modular monoliths & microservices
- Event‑driven architecture with Kafka/Pulsar; CQRS & SAGA
- API‑first: REST, gRPC, GraphQL; versioning & idempotency
- Multitenancy, data sharding, and regional isolation
- Performance: autoscaling, backpressure, circuit breaking, rate limiting