>all of this, written by hand in C++, nothing off the shelf, very minimal dependencies (OpenSSL being the only one of note), everything running on Windows and completely bespoke
Great engineering but this is the time you could have spent building your core competency. re-inventing the wheel is a good recipe for failure
In 2014 Kubernetes didn't exist and the alternatives all had downsides. I was in charge of a non trivial deployment then and I also did extensive research and decided to build something bespoke on top of docker.
There's a reason Google had Borg and all the other big companies had their internal systems. Those were not reinventing the wheel, they were just building wheels round enough to hit the highway.
By the time our product launched Kubernetes had come out and we could migrate to that eventually.
Great engineering but this is the time you could have spent building your core competency. re-inventing the wheel is a good recipe for failure