One of the main differentiators we see is that frameworks like SAM or Serverless are pretty opinionated about how your app should be defined/structured/implemen

One of the main differentiators we see is that frameworks like SAM or Serverless are pretty opinionated about how your app should be defined/structured/implemented. These frameworks work absolutely great, as long as you 100% buy in to their way of doing things. This creates a certain lock-in effect, and may make it harder to switch to a different framework/approach later on. LocalStack takes a different approach by working on the API emulation layer - hence making it easier to switch and integrate with various different application development frameworks. Btw - there's also a Serverless plugin, as well as a "samlocal" command line - in case you'd like to give it a try: https://github.com/localstack/serverless-localstack https://github.com/localstack/serverless-localstack https://github.com/localstack/aws-sam-cli-local https://github.com/localstack/aws-sam-cli-local