I really enjoyed your post too! I would be interested in more details around the "100s of hours". I want to try a k8s setup like yours, but after investing those 100s of hours into my Flask setup it's hard to justify spending that time again for something else when this already works.
Also interested in the costs for your setup. My costs are in my other comment [1].
[1] https://news.ycombinator.com/item?id=26740911