
You’ve been there: Your Unit tests pass both locally and in CI. You deploy with confidence. You thought.. Then staging in the real cloud reveals the truth—bugs that only show up with actual RDS parameter settings, real SQS and SNS throughput limits, or Lambda and API Gateway behaviour your local mocks never captured.
The solution is Testcontainers.
Testcontainers is a testing library that provides easy and lightweight APIs for bootstrapping integration tests with real services wrapped in Docker containers. Using Testcontainers, you can write tests talking to the same type of services you use in production without mocks or in-memory services. Spin them up, run migrations, execute your Node.js service against them, assert results, auto-cleanup.

In this video, you'll learn how to set up and integrate LocalStack's Snowflake Emulator to develop and test your Snowflake data apps in your local environment or CI pipelines. Whether you're using Snowpark, various client libraries, or building interactive data apps with frameworks like Streamlit, this emulator simplifies your developer experience. We'll walk you through step-by-step instructions on installing the Snowflake emulator with the LocalStack CLI & Docker, configuring and integrating the emulator with popular SQL clients, such as DBeaver, and running SQL queries locally to replicate a full Snowflake environment without cloud dependencies. ⚡ Get early access! The Snowflake Emulator is currently in public preview—reach out to us for access and start building today!

Real cloud developers aren’t pushing straight to AWS. They’re building and testing everything locally before a single deploy goes live. This episode breaks down the modern cloud dev workflow and how tools like LocalStack make it possible to move fast without burning money (or trust). Learn how local-first dev culture is changing the cloud game.

LocalStack Applications in Developer Hub provides sample templates to help LocalStack users adopt real-world scenarios to rapidly and conveniently create, configure, and deploy applications locally.
Getting started
In this demo, we will setup a Sagemaker on Localstack