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This post outlines how RPC works.
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How do hundreds of internal services at a company like Netflix or Google talk to each other? And that too, at millions of times per minute?
A standard REST API, while great for public use, often creates too much overhead for this internal, high-speed chatter. Because it typically uses text-based formats like JSON. While easy for humans to read, it’s inefficient for services that need to have millions of conversations per day.
Instead, these services need to talk in a language that is incredibly compact and fast for computers to process. Plus, they need a pre-agreed set of rules, like a shared blueprint, that guarantees both sides know exactly how to talk to each other without errors.
And most importantly, it should offer a good developer experience without sacrificing performance.
Modern applications use many distributed services. Yet this creates a core challenge:
How to achieve extreme machine-to-machine efficiency? A function call across a network should feel as simple as a local one.
The answer is Remote Procedure Call (RPC). It’s a protocol designed for high-performance internal communication.
Onward.
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What Is a Remote Procedure Call
Let’s dive in!
RPC is a protocol that allows a function call to cross from one program’s address space into another. This frees the developer from manually managing the raw network connection points (sockets) or translating data into a sendable format (serialization).
When your code calls a function like math.sqrt(9), you aren’t concerned with the complex algorithm running inside the math library. You simply trust its public API and know the function’s signature.
RPC extends this exact concept across the network.
The client application gets a stub object - a local proxy that mirrors the remote service’s API. But its methods contain only the logic to forward the call over the network. When you call a function on this stub, it handles all the complex network communication behind the scenes to execute the code on the server.
So, a call like result = paymentService.charge(userId, amount) doesn’t call the payment logic directly. Instead, it calls a local proxy method, which then makes a remote operation. This makes the remote call feel like a simple local library call.
Before we go further, let’s understand this first: