You split your MVP into 12 microservices before you had 100 users. Now a simple feature requires coordinating 4 teams, 6 deployments, and debugging across 8 services. The architecture that was supposed to scale you faster is the reason you ship slower than your competitors.
You deploy a migration that runs ALTER TABLE on a 40-million row table. PostgreSQL rewrites the entire table. Your app is stuck waiting for the lock. Users see 503s for 8 minutes. Schema changes on large tables require a completely different approach.
Month 1 — queries are fast. Month 6 — users notice slowness. Month 12 — the dashboard times out. The data grew but the indexes didn''t. Finding and adding the right index is often a 10-minute fix that makes queries 1000x faster.