All of my lambda functions are a thin Node wrapper on top of Go applications.
The go application is simply a command line accepting JSON via stdin (from the Node wrapper). It is a Joy to test, you can run it locally/independently etc...
[Edit]: Typos fix
https://github.com/KensoDev/sns-lambda-notifier-golang
It's simple enough to understand with absolutely no documentation. But here's the gist.
You develop in Go, you can run tests or run it independent from the lambda and then, when you want to deploy you run `release.sh`.
This is perfect for web callbacks, SNS notifications etc...