Local development and testing are significant for engineers who wish to ship confidently onto production environments. Test-driven development (TDD) has been adopted as an essential practice to enforce that and ensure that every code change is validated locally and on CI. This is where we arrive at the Testcontainers libraries that support your tests, providing lightweight, ephemeral instances of common databases, message brokers, web browsers, or anything else that can run in a Docker container. With Testcontainers, available in different popular languages: Java, Go, .NET, JavaScript/Typescript, and Python, you can replicate the production environment on your local machine and test everything (including AWS APIs powered by LocalStack)! Testcontainers ensure that the data access layer, user interface, and application are tested well at each step. In this session, we have looked at Testcontainers and how to adopt them to develop our applications locally and run our integration tests while using LocalStack to provision cloud resources inside a Docker container before pushing your application to production! In the end, we have also discussed how LocalStack and the Java version of Testcontainers play nicely with each other and wind up with updates about the all-new LocalStack release!

LocalStack's cloud emulator lets you run Amazon Elastic Container Service (ECS) clusters and tasks on your local computer. It's sometimes useful to mount code from the host filesystem directly into the ECS container. This helps quickly test changes without needing to rebuild and redeploy the ECS Task's Docker image each time. This video explains how to use code mounting with the ECS bind mounts feature.

We’re partnering with gdotv to simplify development with our Amazon Neptune cloud emulator component. You can now easily query, visualise and model your graph data either interactively or using the Gremlin querying language with G.V() - Gremlin IDE. With G.V(), you can considerably enhance your graph database development experience whilst gaining access to a powerful reporting and visualisation toolset for your production data. With LocalStack’s core cloud emulator, parity is ensured between a local Neptune instance and AWS’s own, meaning Gremlin queries in your development environment will behave identically on Amazon Neptune. In this video we demonstrate how to use G.V() with LocalStack Neptune.

Debugging serverless functions has always been challenging, often requiring repeated invocations, extensive log tracing, and cloud deployments to diagnose an issue. The new Lambda Debug Mode in LocalStack changes this by allowing developers to debug AWS Lambda functions directly in their IDE, with breakpoints, variable inspection, and step-through execution, without leaving their local environment. In this presentation, Marco Edoardo Palma provides a hands-on demo of Lambda Debug Mode—from debugging standalone functions to handling multi-function workflows. Learn how this developer-first approach makes debugging serverless applications faster, smoother, and more intuitive.