I use Lambda specifically for creating thumbnails. My blog post about it: http://www.pesfandiar.com/blog/2017/03/10/serverless-photo-s...
2. Endpoint for collecting anonymous usage stats in our apps.
The functionality was so small and temporary it was great to be able to not need to provision anything and not even pay (our usage is under the free tier).
The regex to deal with error handling and API GW in general were pretty clunky. The Lambda was a self contained and unit/integration tested Java project.
Add a specific label in Github PR => Listen to Github PR webhook => Trigger e2e tests in CI for that branch
Nice things scalability, not taking down the site if there is a segfault, and cost. Can run a smaller webserver and PAYG on the functions overall it costs less.
It is a lot cheaper than a "proxy as a service".
I have a toy service with ~200k requests/day to a public service and I was blocked all the time.
After I changed to use API Gateway + Lambda as a proxy, never had these problems again. I just monitor the 4xx and 5xx errors and they are almost zero now.