Authentication Systems: DIY vs Managed

I built identical Flutter apps with login/signup flows—one using a Spring Boot backend I wrote from scratch, one using Supabase. Same features, different approaches. Here's what I learned.

Spring Boot Version

Complete control, but you handle everything—token refresh, password hashing, email verification, session management. It's educational but time-consuming.

Supabase Version

Fast to ship, but you're tied to their ecosystem. Great for prototypes and startups with tight deadlines.

The Tradeoff

Time-to-market vs flexibility. The answer depends on your constraints. If you're a startup trying to prove product-market fit, use managed services. If you're building a core competency, build it yourself.