I've worked on a complex bookkeeping SAAS. Our "CVS" im- and export was the most used feature by far.

Yet it was implemented on a thursday afternoon by a junior, using the first "library" that popped up in a google search. And over the years, leaked into every corner of the application. Unaffordable technical debt.

I cemented this experience into memory and now, in every new gig where I have to do "CSV", I isolate it, abstract it, overengineer it. Hell, last year I even built and launched a dedicated e2e tested csv-export service instead of just `from csv import writer` and call it a day.

Because CSV is the "interface" that will bring your system down if not properly designed.