
Silvio and Carole introduce lstk, LocalStack's next-generation CLI built from scratch in Go. They explain why the team rebuilt the CLI, walk through its key features — zero-config startup, seamless browser-based authentication, and a rich interactive TUI that surfaces real-time progress and actionable errors — and demo how lstk gets you from install to a running emulator in seconds. They also dive into the architecture behind lstk and how it is designed to support multiple emulators, flexible runtimes, and deep integrations with CI pipelines and IDEs.

LocalStack is a cloud service emulator designed for local development and testing of cloud applications. With LocalStack, you can test AWS CloudWatch metric alarms, to get notified on infrastructure failures — all on your local machine! In this video, you will learn how you can use a CloudWatch metric alarm to get notified automatically when your Lambda function invocations fail. You will also set up an email notification using the Simple Email Service (SES) and our Mailhog extension.

Testing in the cloud = slow builds, fragile staging, surprise bills. Let’s talk about how developers are flipping the script and using local cloud environments to test smarter, faster, and cheaper without breaking production. Bonus: You’ll learn how LocalStack lets you simulate AWS on your machine. Game changer.

Why wait for the cloud to test your app? In this episode, we’ll write and run an integration test to validate our LocalStack app. You’ll learn how to upload a file, trigger the Lambda-SQS-DynamoDB flow, and assert the results all locally.