Design systems and lead technically.
2 topics
Monolithic (single unit, good for small teams), microservices (independent services, team autonomy), event-driven (loose coupling, eventual consistency), serverless (zero infra, pay-per-execution), modular monolith (clear boundaries without distributed complexity). Start monolith, extract services when needed. Document with ADRs.
2 resources
SOLID, DRY, KISS, YAGNI. Enterprise patterns: Repository, CQRS, Event Sourcing, Saga, Circuit Breaker. DDD: bounded contexts, ubiquitous language, aggregates, domain events. Architecture is about tradeoffs — document decisions and their reasoning.
Scalability: horizontal scaling, sharding, caching (Redis), CDN, read replicas, message queues. Reliability: redundancy, replication, health checks, graceful degradation, bulkheads, chaos engineering. Define SLOs/SLIs. Availability: 99.9% = 8.7h/year downtime. Latency budgets: P50/P95/P99.
Choose by access patterns: relational (ACID), document (flexible schema), key-value (caching), graph (relationships), time-series (metrics), search (Elasticsearch). CAP theorem tradeoffs. Data flow: sync APIs, async messaging (Kafka), event sourcing, CDC. Strong vs eventual consistency decisions.
1 topic
Communicate to diverse audiences: execs (business impact), engineers (technical detail), PMs (feasibility). C4 model for progressive-detail diagrams. ADRs document decisions. Lead design reviews, architecture reviews, post-mortems. Build consensus via RFCs. Stay hands-on enough to evaluate proposals credibly.