Spin is a local development orchestrator that launches your applications directly on the host.
You know what sucks? Compiling and running your app & unit tests the compiling and running it again so that you can run integration tests in Docker.
You know what else sucks? Trying to debug an application running inside a Docker container.
Want to run two different branches of your app and its dependencies simultaneously? Spin has your back!
All resources e.g. IP addresses, ports, files are automatically allocated from a pool so that multiple running environments never conflict with each other and no ENV var hacking is required.
Want to point part of your local stack at a production service? In Spin every definition is lazily evaluated which makes it possible to just redefine one let binding at the top-level and everything else in your stack will see the new definition.