every bit of business logic was implemented in Stored Procedures and Triggers on a MSSQL database.
Provided the SP’s are managed in a CVS and pushed to the DB via migrations (similar to Entity Framework), this is simply laborious to the devs. Provided the business rules are simple to express in SQL, this can actually be more performant than doing it in code (although it rarely ever is that simple).
There were no frontend code either on the server, users have some ActiveX controls installed locally that accessed the DB.
This is the actual WTF for me.
There was no version control at all. The company that provided the software was really shady, and the implementation was so bad that the (only) developer was there full time fixing the code and data directly in production when the users had any issue (which was several times a day).