FTA:
* Kubernetes has a huge amount of traction in the DevOps landscape, with managed implementations from all the major cloud vendors and virtually endless training materials and complementary technologies.
* Kubernetes is open source, which was a major plus: it meant that we could avoid vendor lock-in and implement local development environments that mimic production.
* Kubernetes has a large feature set that fit well with our requirements, including our more exotic necessities like autoscaling based on custom metrics.
AFAIK none of those are true of AppEngine.
the appeal of AppEngine is that you don't need DevOps, google manages and monitors services for you.
Definition of 'hype' here :)
AppEngine has an enormous number of limitations that you only hit once you scale up and gets very expensive very quickly.
I have used AppEngine in production for about 50+ clients and I am genuinely really curious to know what these limitations are. Maybe it is dependent on the programming language/framework? I run Phoenix/Elixir with Vue.JS + PostgreSQL as standard for most of my clients, it's really a breeze to work with.
In addition, these are the advantages of working with AppEngine:
This is a huge success story that I was part of: https://cloud.google.com/customers/gearlaunch/
At our peak, we were processing $500,000 of online orders per day and spending about $5k/month on our entire GPC bill. It was a rounding error compared with our income.
The biggest expenditure was actually on the Postgres database servers that we needed for our analytics, not on AppEngine.