I prefer to use a SQLite database. And if a customer insists on CSV then I still use a SQLite database to import and/or export the CSV without them realising it. SQLite brings sanity to CSVs.
You misunderstand how enterprise integrations work. It's easy to tell a customer: "your CSV is not compatible with standard off the shelf tooling, indeed the most popular database engine in the world" than "your CSV doesn't seem to work with our software/library/<proprietary ETL framework>". The former makes it their problem, the latter will almost undoubtably make it your problem. In case you don't know: SQLite has a really well designed and very performant CSV import function. BTW did you really downvote me for that? Wow.
