We use Node.JS lambda functions for real time image thumbnail generation and scraping needs. As well as mirroring our S3 buckets to another blob storage provider and a couple of periodic background jobs. It works beautifully. It's a little hard to debug at first but when it's set up, both pricing and reliability is really good for our use cases.

I think a lot of people try to use the "serverless" stuff for unsuitable workloads and get frustrated. We are running a kubernetes cluster for the main stuff but have been looking for areas suitable for lambda and try to move those.