Took over a project where a dev created a table with no primary key and enforce a unique constraint in code. Wtf? He also always selected top 1 so if you added a record directly in the table it completely fucked the expected data.

So, when I took this piece of shit over I didn't realize what the table was and when I tried to convert it to EF it barfed since there was no PK. Was a complete PITA and had to create all new tables.

Some people shouldn't develop software!!!!!!!!!