There are tens of thousands of engineers maintaining and supporting postgres and clickhouse in all the organizations where they are used, the vast majority of which are not on Twitter's scale.
Tens of thousands across all the organizations where postgres and clickhouse are used, maybe (though even then probably not!).
Not tens of thousands at any one organization supporting postgres and clickhouse.
No single organization needs even hundreds of people to support these apps. You just need a good architecture and a handful of dba's, developers, and sysadmins... maybe.. depending on your scale. At many smaller orgs you can probably get away with one.
This 100%.
You don't need 10'000 engineers to run billions of queries.
It's not like the SREs are running the queries themselves.
Your job as an SRE is to design and run computer systems, not to become the computing platform yourself.
