Design a Scalable Microservices Architecture

Design a scalable microservices architecture.

Inputs:
System goal: {SYSTEM_GOAL}
Traffic expectation: {TRAFFIC}
Service boundaries: {DOMAINS}

Provide:
1. Service decomposition
2. API interactions & contracts
3. Data storage per service
4. Event-driven or REST design decision
5. Observability (logs, metrics, tracing)
6. Scaling & failover strategy
7. Deployment architecture diagram (text form)