How gRPC Turns a Local Method Call into a Network Request

A ride-hailing example shows how hand-written JSON calls between services can break silently when a field is renamed, such as driver_id changing to driver_ref. gRPC instead starts from a contract-first .proto file that defines typed messages and service methods. A compiler generates a client stub that lets callers invoke remote methods like local functions. Each field's numeric identifier, not its name, governs the binary wire encoding. The approach hides serialization and transport details but not latency, failures, or contract versioning, and it requires a build step to regenerate code whenever the contract changes.