I am publishing a book in the following months that covers all the items you mention, IAM, fully Cloudformation, deployment with Gradle etc. The language I picked is Java because we thought with the publisher that Java at Lambda has very little written resources. If you are interested here is the link and if you pre-order it you can access to finished chapters already:

https://www.amazon.co.uk/Building-Serverless-Architectures-C...