As a SRE I was going to make a comment about missing basic metrics like RED or structured logging but at the end you mentioned you like ELK APM and used it so indeed it's very opinionated as ELK is not a ready-to-use cheap solution people would use as their first choice IMHO.
Also, a Show HN usually contains the URL of the project, no need to post a text and then add a comment with the URL.
Oh, I'm using ELK with docker-compose (free community edition). Running it on a 16GB RAM, 4CPU virtual machine. Have been able to use it for all our deployed environments. RPM of 10k+ (maximum), and have been using it for 5+ months now. And we retain data for 30 days
Though an FYI, we have only 6 web apps. Maybe that's why it's been working fine for us all this while
Post without a main URL have a penalty here, so it's more difficult that they reach the front page. Next time make a post with an URL and then add a comment explaining that you wrote it.