I Migrated Our API From REST to GraphQL. Here's What Nobody Warned Me About.

We spent 3 months migrating our main API. The benefits are real. So are the headaches nobody talks about.

Why We Switched

REST endpoints were multiplying like rabbits. Mobile needed different shapes than web. The versioning nightmare was real.

Week 1-4: Schema design. This is where most teams underestimate. A bad schema haunts you forever.

Week 5-8: Resolver implementation. N+1 query problems hit hard. We had to implement DataLoader everywhere.

Week 9-12: Client migration. Web first, then mobile. Both had different caching strategies.

Query-level permissions. No more endpoint explosion. Type safety across the stack. The mobile team stopped asking us for new endpoints.

Error handling is brutal. A partial success in GraphQL means you're sending 200 with partial errors in the response body. Clients don't expect that.

Caching is harder. HTTP caching doesn't apply. You need application-level caching.

Monitoring is different. Each query is unique. Traditional request metrics don't tell you much.

For our use case, yes. For a simple CRUD API? No.

What's your API architecture?