[derriz]

One selling point is “free” horizontal scaling possibility. Contrived example: you’ve a parallelizable workload but the work arrives sporadically. 600 pieces of 10 minutes work arrive. In theory, instead of waiting 10 hours to process the batch on a single instance - lambda will fire up 600 instances completing the batch in 10 minutes. And 1 cloud CPU for ten hours costs the same as 600 for 10 minutes.

In practice, you spend more time writing lambda specific code and changing an obvious workflow to avoid DB access becoming a bottleneck or debugging why published events did not trigger the correct function, etc. that you wonder whether throwing cpu/memory/disk resources at a single instance tuned for the workload with dedicated local SSD storage might have been a better option especially as tasks around logging, persistent storage, debugging, profiling, error handling and getting stack traces are so much easier.