I do wonder if, in a few years time, if we're not going to be seeing a new genre of technical blog posts: "How we migrated off serverless to reduce our costs"
It's already started: https://medium.com/coryodaniel/from-erverless-to-elixir-4875...
I wonder if the fact that application load balancer can now invoke lambda functions could've made serverless viable. https://aws.amazon.com/about-aws/whats-new/2018/11/alb-can-n...
Mind you, the post was written in August 2018 and the above announcement was made in December 2018.