Introduction

You Already Know Enough to Start

If you're reading this, chances are you've been writing Ruby for a while.

You've built Rails applications. Maybe you've launched products, worked on teams, or maintained a monolith that's held together by duct tape and chewing gum. You're comfortable with controllers, background jobs, maybe even a bit of Redis and Sidekiq. You've seen things.

But at some point, the buzzwords crept in.

"We're moving to microservices."

"Serverless is the future."

"We should just rewrite this part in Node."

And just like that, your experience suddenly felt... outdated. Not because your skills disappeared, but because the industry started fetishizing scalability and serverless architecture, and forgot that Ruby developers can do it too.

Here's the truth: you don't need to throw away everything you know just to build modern systems. You don't need to learn Go. Or Node. Or Python. You can build production-grade, massively scalable serverless systems, in Ruby.

That's what this guide is about.

Why I Wrote This Book

Over the past five years, I've built dozens of AWS Lambda functions in Ruby.

These weren't toy examples or weekend hacks. They've powered real systems, processing millions of files, ingesting tens of millions of API events, and triggering pipelines that were previously crippling my rails apps.

And despite what you've heard about Ruby being slow or expensive in the cloud, these Lambda functions are some of the cheapest, fastest, and most reliable parts of my infrastructure.

But it wasn't easy to get here.

AWS's documentation barely mentions Ruby. The tutorials are all for Node and Python. The tooling is scattered, the examples outdated, and nobody tells you what actually works in production.

So I wrote the guide I wish I had when I started.

Who This Guide Is For

This guide is for Ruby developers who want to modernize their stack without abandoning the language they love.

You might be:

A solo developer looking to offload heavy processing to the cloud
A Rails engineer trying to integrate event-driven features
A team lead exploring cost-saving alternatives to background jobs on EC2
A startup CTO ready to scale parts of your system without rewriting everything

You don't need to know Docker. Or Terraform. Or AWS. This guide will give you the minimum viable knowledge to get real work done without getting lost in DevOps hell.

What You'll Learn

In this guide, we'll walk through exactly how to:

Write Lambda functions in Ruby and package them using Docker
Deploy functions using Terraform, without needing to understand every AWS acronym
Set up real-world event sources: S3 triggers, SQS queues, Kinesis streams, and API Gateway endpoints
Build complete pipelines that move data between services, your Lambdas, and your Rails app
Integrate Rails and Lambda, using them together as a hybrid architecture
Orchestrate workflows, build fault-tolerant systems, and optimize costs in production

Each section includes code templates, copy-paste-ready Terraform, and real-world use cases that have been tested in battle.

What You Won't Learn

This isn't a deep dive into the internals of Docker or Terraform.

If you're looking for a comprehensive AWS certification course or a DevOps engineer bootcamp, this isn't it.

We're staying practical and focused, just enough to get powerful things done as a Ruby developer. You'll get working Lambda functions into production before the AWS docs would have you past the "What is Lambda?" page.

How to Use This Guide

Start from the beginning and build your understanding piece by piece. Or jump to a chapter that solves your problem right now. Either way, treat this as a toolbox.

Each chapter builds toward a set of reusable tools, code, and strategies you can apply across projects.

Ruby Isn't Dead, It's Evolving

This isn't just about keeping Ruby relevant. It's about reminding developers that Ruby is still one of the most productive, expressive, joyful languages in the world.

The future of Ruby includes the cloud.

Let's build it, function by function.