Great write-up. Note that the author is only serving 70 requests per second at peak with 15 thousand registered users and 3 thousand in revenue per month. This just shows that you don't always have to plan to scale to thousands (or millions) of requests per second.

This blue-green deployment workflow reminds me of a similar setup used by the creator of SongRender[1], which I found about via the running in production podcast[2]. One thing to be aware of with smaller VPS providers like Linode, DO, and Vultr is that they charge per hour rather than per second. So if you boot up a new VM every time you deploy you're charged for a full hour each time.

[1] https://jake.nyc/words/bluegreen-deploys-and-immutable-infra...

[2] https://runninginproduction.com/podcast/83-songrender-lets-y...