Every engineering team hits this conversation at some point.

Someone proposes GraphQL. Someone else says REST is fine. A third person mentions gRPC and half the room goes quiet.

The debate usually ends with the most senior person in the room picking what they're most familiar with. That's not a strategy — that's habit.

Here's an objective breakdown of all three, when each one wins, and how to actually make the decision for your specific use case.

The Core Mental Model