I don’t get it. This whole thing says single writer does not scale, so we stopped writing as much and removed reads away from it, so it works ok and we decided that’s enough. I guess thats great.
There's nothing novel about optimizing queries, sharding and using read replicas.
For that reason, I find it actually bold that they disclosed it, and I appreciate it.
The article reminded me of a similar post about MySQL use for Facebook from the Meta team, which had the same message: big database servers are powerful workhorses that scale and are very cost-effective (and simpler to manage than distributed setups where writes need be to carefully orchestrated - a very hard task).
The two core mesages of both articles combined could be read as: 1. big DB servers are your friend and 2. keep it simple, unless you can't avoid the extra complexity any more.
They had huge problems with VACUUM at high tps. Basically the database never had space to breath and cleanup.