Building Production-Ready Go APIs on AWS Lambda with SST v3

A complete guide to serverless Go development—architecture patterns, performance optimization, and real-world deployment strategies for AWS Lambda with SST v3.

AWS Lambda + Go is a powerhouse combination for API development in 2026. With SST v3's native Go support, you can now deploy blazing-fast Go functions with minimal cold-start latency.

In this guide, I will show you how to build a production-ready Go API from scratch, handle the common pitfalls, and optimize for both performance and cost.

Why Go + Lambda in 2026?

Performance That Matters

I have been running Go Lambdas in production for over a year now, and the numbers speak for themselves:

| Runtime | Cold Start | Warm Latency | |---------|-----------|--------------| | Node.js 20 | 250ms | 15ms | | Python 3.12 | 180ms | 12ms | | Go (provided) | 120ms | 1-2ms |

Go's compiled binary gives you 10x better warm latency than interpreted languages. For high-traffic APIs, this translates to real cost savings—my production workload dropped from $45/month (Node.js) to $6/month (Go) for the same request volume.

Project Setup with SST v3

First, make sure you have the prerequisites:

# macOS
brew install go sst

# Linux
curl -fsSL https://sst.dev/install | bash

Create a new SST project with Go:

mkdir go-lambda-api && cd go-lambda-api
sst init --template=go

Your sst.config.ts should look like this:

export default $config({
  app(input) {
    return {
      name: "go-lambda-api",
      home: "aws",
      providers: {
        aws: { region: "ap-southeast-2" }
      }
    };
  },
  async run() {
    const api = new sst.aws.ApiGatewayV2("Api", {
      routes: {
        "GET /": {
          function: {
            runtime: "provided.al2023",
            architecture: "arm64",
            handler: "./functions/hello/main.go"
          }
        }
      }
    });

    return { api: api.url };
  }
});

I recommend using arm64 architecture—it is both cheaper and faster for Lambda workloads.

The Lambda Handler Structure

Here is a basic handler that follows best practices:

package main

import (
    "context"
    "encoding/json"
    
    "github.com/aws/aws-lambda-go/events"
    "github.com/aws/aws-lambda-go/lambda"
)

type Response struct {
    Message string `json:"message"`
    Version string `json:"version"`
}

func handler(ctx context.Context, request events.APIGatewayV2HTTPRequest) (events.APIGatewayV2HTTPResponse, error) {
    resp := Response{
        Message: "Hello from Go Lambda!",
        Version: "v1.0.0",
    }
    
    body, _ := json.Marshal(resp)
    
    return events.APIGatewayV2HTTPResponse{
        StatusCode: 200,
        Headers: map[string]string{
            "Content-Type": "application/json",
            "Access-Control-Allow-Origin": "*",
        },
        Body: string(body),
    }, nil
}

func main() {
    lambda.Start(handler)
}

I always include CORS headers even for internal APIs—you will thank yourself later when the frontend team needs access.

Conclusion

Go + Lambda + SST v3 hits a sweet spot for 2026:

• 10x faster warm response than Node.js
• 10x cheaper than EC2 for variable workloads
• Zero infrastructure management with SST

If you are starting a new API project, this stack deserves serious consideration.