This problem doesn't go away with postgres. It's totally anecdotal but this is one thing that I've noticed different in mysql shops and postgres shops - with mysql there is usually at least one person on staff who knows MySQL DBA and scaling pretty well, with postgres it's rarely the case to have someone who knows the internals well - like you said, the person capable of maintaining it when it goes wrong.

You could argue it's because postgres requires less poking though I would say you don't need the DBA for when things go right.

Of course most people are just handing the management off to the cloud and that's potentially why, but it doesn't cover everything

There are two sizes of companies: those that can afford '1+ dedicated ____-person' and those that can't. Which should filter through to technology choices more than it does.

I mean, with this custom thing, you have that question as well with downside is you cannot pick up the knowledge from off the street.

I became the Kafka guy at my current company, it took me about a week of reading and every time I had further question, I didn't have to bother anyone, I could Google and get data I needed.

When it's some NIH thing, you have to bother coworkers and knowledge is whatever is in YOUR company knowledge base with no ability to get knowledge from outside the company.

EDIT: You could also leverage contractors or outside support if not homegrown software.

Nose goes