My first job out of college (2007) involved a lot of removal of early 2000s one-off custom payment processing code. Access DBs full of years worth of credit card numbers, code that just emailed the credit card details to the site owner without keeping a record, etc. It was definitely a different world. Most of them, I just switched to PayPal shopping cart and checkout. In retrospect, I didn't know wtf I was doing and probably shouldn't have been working on it.