As a hobby, I'm working on a project that allows you to run a subset of the AWS infrastructure on your local machine. Yes, there are related projects such as Serverless and more recently LocalStack from Atlassian but my intent is to focus solely on Lambdas written in Java and I'm learning a lot about the AWS APIs and orchestration semantics along the way. I try to leverage existing open source projects (DynamoDBLocal, Kinesalite, etc.) running in Docker containers and provide the glue to do things like spin up an entire system locally while being able to debug Lambdas, etc. I'm working on it in the open here: https://github.com/digitalsanctum/lambda