This is related to the story itself and some of the comments, but when I was working for an org that acquired a lot of other companies as part of its normal business, I once walked into an acquisition that tracked all of its transactions on two million separate Excel spreadsheets. Yes, you read that right: 2,000,000 spreadsheets.
All manual — no accounting system and no automation of any kind. Also, their backups were basically non-existent.
That was a fun one to convert to some form of reliability and modernity.