gRPC

gRPC is one of the most important backend architecture tools to include because it solves a very different problem from GraphQL. It is built for typed remote procedure calls, efficient service-to-service communication, streaming, and polyglot systems that want strong contracts with lower overhead than typical JSON-over-HTTP APIs. That makes it especially relevant inside distributed backends, internal platforms, mobile-to-backend pipelines, and infrastructure-heavy environments.

Its economics are simple at the framework level. gRPC is open source and free to use under the Apache 2.0 license. The official site does not publish a SaaS pricing page because the framework itself is not sold that way. The real cost comes from the systems built around it: platform tooling, traffic, observability, schema governance, and developer workflow complexity. Like GraphQL, that means gRPC is an architectural choice first and a commercial line item only when vendors are layered on top.