This one is listed as design, but it could just as easily count as architecture. Guessing a lot developers have worked on scaling with lambda functions or a complex IAC setup when a simple API running on a small VPS would have done the trick, at least until enough people are using the application for it to be considered profitable.
When we dockerized a service the p95 time in testing notched up a noticeable amount. I was already juggling so much other work at that point that for shits and giggles I tried vertically scaling - reducing the cluster size by half and the cores per server by 2x. Zeroed out the p95 delta.
OPS gave me shit about it, and I was like kiss my ass, the cluster costs EXACTLY the same and deployments are 25% faster.
I think people forget that in the cloud, bigger servers don't really cost more until you get crazy about it.
This one is listed as design, but it could just as easily count as architecture. Guessing a lot developers have worked on scaling with lambda functions or a complex IAC setup when a simple API running on a small VPS would have done the trick, at least until enough people are using the application for it to be considered profitable.