Author Charles Stross has been writing a series of posts about his former life in the software industry. Read it to destroy your belief that important software and internet services are generally written by people who know what the hell they’re doing.
Often, what you have is what Stross describes here: one stressed out programmer maintaining a Gordian knot of code that was only ever meant for demo use, but then somehow it ended up in production and now they can’t ever get rid of it. From which point possible futures include burnout, bankruptcy, or gigantic profits.
Stross left the industry at about the time that I entered it, around 2000. His publishing career has since included novels that combine H. P. Lovecraft with IT, and I now understand why. My own experiences have been less harmful to sanity, (except that first part time job where I wrote a webmail solution in C, which to you non-programmers out there is like inventing and building your own car because you’re too lazy to learn how to drive a real one.) On good days I even feel like I know what I’m doing. Then the bug reports start coming in.