I have more experience running large MySQL databases. Both at SurveyMonkey and Zapier our primary databases were MySQL and were massive as you can imagine from massively scaled consumer products. I won't list the data here since this is about postgres but wanted to provide the context.

The largest postgres I've personally administered is on RDS:

  * postgres 13.4
  * db.m6g.2xlarge (8vCPU, 32 GB RAM)
  * 1.3tb storage
  * Largest tables: 317GB, 144GB, and 142GB

I effectively treat this database as an analytics database and write massive queries with joins against those largest tables and postgres handles it just fine.

I have had random bad query plans when using CTEs that get cached and take down the entire DB for a bit but usually been able to fix it with `vacuum analyze` and the customizing the query to convince postgres to choose a better plan.

Overall I think postgres can do a lot of work with very little.