What is gRPC?: Why Developers Love It (and Some Hate It) – With a Complete Node.js Example

Last updated on April 22nd, 2025

Introduction: What Is gRPC and Why Should You Care?

In today’s fast-paced, microservice-driven world, performance and scalability are more than just nice-to-haves—they’re essential. REST APIs have long been the go-to for communication between services, but now, gRPC (gRPC Remote Procedure Calls) is shaking things up.

Built by Google, gRPC is a high-performance, open-source universal RPC framework. It’s gaining massive popularity for its efficiency, especially in systems where low latency and high throughput are critical. In this article, we’ll dive deep into what makes gRPC so powerful, explore its pros and cons, and walk through a complete, beginner-friendly example using Node.js.

By the end, you’ll understand:

• Why gRPC is a game-changer for microservices
• How it compares to REST
• How to implement a working gRPC service in Node.js
• Best practices and tips from a senior software engineer

Let’s get started.

What is gRPC?

gRPC stands for Google Remote Procedure Call. It’s a modern open-source framework that allows services to communicate with each other efficiently, using Protocol Buffers (protobufs) instead of JSON.

Key Features of gRPC:

• Fast: gRPC uses HTTP/2 under the hood, allowing multiplexing, binary framing, and header compression.
• Strongly Typed: Thanks to Protocol Buffers, your data is structured, typed, and compact.
• Cross-language Support: gRPC supports multiple programming languages (Node.js, Go, Java, Python, C++, etc.)
• Bi-directional Streaming: Both client and server can stream messages to each other.
• Contract-first API Design: You define the API in a .proto file before writing any code.

REST vs gRPC: A Quick Comparison

Verdict: If you’re building an internal system or microservices architecture, gRPC is often the better choice. For public-facing APIs, REST is still more practical due to better browser compatibility.

When Should You Use gRPC?

✅ Ideal Use Cases:

• Microservices architecture
• Real-time communication (chat apps, IoT, game servers)
• High-performance systems (financial platforms, video streaming)
• Multi-language backend environments

❌ Not Ideal For:

• Public APIs where browser compatibility is important
• Systems where human readability of payloads is critical
• Simple CRUD APIs where REST is easier to maintain

Setting Up gRPC with Node.js: Complete Example

Now that you understand the theory, let’s implement a basic gRPC service in Node.js. We’ll build a simple “Greeter” service where the client sends a name, and the server replies with a greeting.

🛠 Prerequisites

Make sure you have:

• Node.js installed
• protoc (Protocol Buffers Compiler)
• grpc-js and @grpc/proto-loader npm packages

mkdir grpc-nodejs-example
cd grpc-nodejs-example
npm init -y
npm install grpc-js @grpc/proto-loader

Step 2: Create a .proto File

Create a folder named protos and add greeter.proto inside it.

protos/greeter.proto

syntax = "proto3";

package greeter;

service Greeter {
  rpc SayHello (HelloRequest) returns (HelloReply);
}

message HelloRequest {
  string name = 1;
}

message HelloReply {
  string message = 1;
}

Step 3: Implement the gRPC Server

server.js

const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');
const path = require('path');

const PROTO_PATH = path.join(__dirname, 'protos/greeter.proto');

const packageDefinition = protoLoader.loadSync(PROTO_PATH);
const greeterProto = grpc.loadPackageDefinition(packageDefinition).greeter;

function sayHello(call, callback) {
  const name = call.request.name;
  callback(null, { message: `Hello, ${name}!` });
}

const server = new grpc.Server();
server.addService(greeterProto.Greeter.service, { SayHello: sayHello });

const PORT = 'localhost:50051';
server.bindAsync(PORT, grpc.ServerCredentials.createInsecure(), () => {
  console.log(`gRPC server running at ${PORT}`);
  server.start();
});

Step 4: Implement the gRPC Client

client.js

const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');
const path = require('path');

const PROTO_PATH = path.join(__dirname, 'protos/greeter.proto');

const packageDefinition = protoLoader.loadSync(PROTO_PATH);
const greeterProto = grpc.loadPackageDefinition(packageDefinition).greeter;

const client = new greeterProto.Greeter('localhost:50051', grpc.credentials.createInsecure());

client.SayHello({ name: 'Manendra' }, (error, response) => {
  if (!error) {
    console.log('Server response:', response.message);
  } else {
    console.error('Error:', error.message);
  }
});

Step 5: Run the Example

Start the server:

node server.js

In a new terminal, run the client:

node client.js

✅ You should see:

Server response: Hello, Manendra!

Congratulations, you’ve just built your first gRPC service in Node.js!

Download the project from this link: gRPC with NodeJS Example

Benefits of Using gRPC (from a Senior Engineer’s Lens)

As someone who’s worked on both small-scale and enterprise-grade systems, here’s what I appreciate about gRPC:

1. Speed: Protocol Buffers are significantly faster and lighter than JSON.
2. Scalability: Easy to break services into smaller microservices.
3. Maintainability: Proto files make APIs self-documenting and less error-prone.
4. Cross-Language Support: Great for teams working with multiple languages.
5. Streaming: Built-in support for client-side, server-side, and bidirectional streaming.

Drawbacks to Watch Out For

1. Learning Curve: Proto files and streaming might be confusing for beginners.
2. Binary Format: Harder to debug and read than JSON.
3. Browser Compatibility: Needs gRPC-Web for frontend communication.
4. Dev Tooling: Not as mature as REST (Postman, Swagger, etc.)

Pro Tips and Best Practices

• 🔐 Use TLS/SSL for secure communication.
• 🧪 Always version your proto files.
• 🚀 Use gRPC health checks and reflection in production.
• 📦 Consider using a monorepo to manage services that share .proto files.
• 🔍 Use grpc-tools for advanced code generation.

Summary

If you’re still using REST for everything, it’s time to consider whether gRPC could serve your architecture better. With blazing speed, structured communication, and modern features like streaming, gRPC is quickly becoming the go-to choice for building reliable microservices.

Whether you’re a beginner or an experienced developer, this complete guide with a working Node.js example gives you the foundation to start building efficient gRPC services today.

Final Thoughts

gRPC is not just a buzzword—it’s a serious tool that’s solving real-world problems for teams that care about performance and scalability. While it’s not a silver bullet, it’s definitely worth learning and experimenting with.

Give it a try in your next project. You might be surprised at how much it simplifies your service communication.

If you found this helpful, don’t forget to bookmark it, share it with your team, and drop your questions in the comments!