- REST is not just pretty urls + json and it does not have 'levels'. HATEOAS is a constrain of REST, if your API does not include it you should stop calling it REST. - REST is a software architecture style and it does not require json (you can use protobufs or anything else really..) - gRPC is not the magic protocol that its going to replace everything, it has its use cases but so are RESTful APIs.