8. Summary: What It All Comes Down To
After going through the docs, case studies, and tradeoffs, here's the takeaway:
1. Start Monolithic: Always start with one. Add MSA after problems emerge, not before.
2. Split only when it hurts: Split when deployment queues get too long or teams get too large. Don't split early.
3. Observability First: Don't split without log aggregation (ELK), monitoring (Prometheus), and distributed tracing (Jaeger). You'll be blind.
4. Database Separation: Won't split databases? Don't do MSA. Distributed monolith is the worst outcome.
5. Conway's Law: Check organization structure first. 5 people? Monolith. 100 people? MSA.
6. Modular Monolith: This is the answer for most cases.
I'm convinced now. Monolith isn't bad. Using it wrong is bad.