I haven't used JAWS, and I don't see where they speak to this question, but I do work on AWS lambda "applications", and typically they're versioned using versioned S3 buckets. It's very easy to continuously "deploy" code artifacts to S3, but only update the revision working on production traffic when you're good and ready. You can also optionally spin up complete duplicates of your infrastructure using the new revision, for exceedingly realistic integration or performance tests.

I'm not really sure what you mean by "tracking," but you can log anything you like from a Lambda function, and include version information in those logs.

I do agree with your analogy and caution, though.