And it doesn't freak you out that you're relying on thousands of lines of code that you've never looked at? How do you verify the end result?
I wouldn't trust thousands of lines of code from one of my co-workers without testing
Do you trust the assembly your compiler puts out? The machine code your assembler puts out? The virtual machine it runs on? Thousands of lines of code you've never looked at...
It's thousands of lines of variation on my own hand-tooling, run through tests I designed, automated by the sort of onboarding docs I should have been writing years ago.