Have used both, and don’t like either. I actually DO like very statically typed schemas, but you can easily do this with json over REST, and using IDLs to generate SDKs.

For gRPC vs. REST, I just don’t see the benefits. Performance wins of gRPC are extremely minimal for most backends, ”push based” workflows can easily be handled with webhooks (or message queues), so why am I throwing out extremely mature technology (and tooling/middleware!) that every dev is very familiar with?

For GraphQL, reducing client/datacentre round trips is nice, but can also easily be achieved with RESTful “coordination” services, that serve the front end specifically, and do nothing but stringing together calls to backend services. Why force people to learn another complex technology for that? “Returning smaller payloads” makes minimal impact in practice, and GraphQL requests are MASSIVE compared to REST requests, so you often end up with a performance loss, not gain. Also, GraphQL requests are way harder to glance at in the browser, you can’t just look for GET /dog/123, you have to peek into all the request bodies. And again, all the great REST middleware stops working, because you’re doing RPC.

Basically I see them both as extra complexity with little payoff.