In fairness to the workplaces that I've been in, documentation for a software stack, or even the product, from 18 months ago may as well be in Swahili for as much good as it would do any new member to the team
Just like the comparison to code quality I often see is any such NASA thread: it's a whole different ballgame when one is sending a spacecraft out, or carrying lives to space, than "I tried to send a Slack message and it did a sowweee,oopsiez"
I've been trying to "learn" the missions more thoroughly by flying them on Orbiter and NASSP, and just the sheer amount and depth of documentation that is accessible today is truly astounding. There's something awe-inspiring about sitting and my computer and looking at the mission plan, only to then not understand the "why" of this particular switch that I'm throwing, to then open a pdf with a "astronaut training booklet" which explains the overview of the thing I'm using, to then open another pdf with the detail technical documentation of it, to then a schematic of the equipment should I at any point (but prob not) ever try building one myself.
Only the _documentation_ effort must be monumental.