Why I Switched from Firebase to Supabase + PostgreSQL (And Cut My Costs 80%)

Disclosure: This post contains affiliate links. We may earn a small commission at no extra cost to you. TL;DR : I migrated a multi-agent AI platform from Firebase to Supabase. The result: 80% cost reduction, actual SQL queries instead of document nesting gymnastics, row-level security that works, and a free tier that's actually usable for production. Here's the complete migration story with real numbers. Let me be direct: Firebase is a great product for certain use cases. But if you're building anything with relational data, complex queries, or multi-tenant architecture, you will eventually hit a wall. I hit it 6 months in. This is the story of migrating AEGIS — a multi-agent AI orchestration system with 16 agents, tenant isolation, and an audit trail — from Firebase to Supabase + PostgreSQL. Not a theoretical comparison. A real migration with real data and real costs. What Was Wrong with Firebase? Nothing was "wrong" with Firebase. It worked. But three problems kept getting worse: 1.