Question
For the last 6 months I've had my java developer build the backend and front end dashboard for my background check business.. There are consistently customer complaints about errors in the whole system, such as not being able to log back in, and trouble filling out the form. He keeps blaming the users instead of fixing the problems.. It's getting frustrating and As I lack knowledge in IT , I do not know how to assess if it's his lack having great skills and pulling the wool over me, or if it is that he says " errors are expected " how do I approach this.
Answer
Sounds like you have a bad apple. Customer complaints should almost never be excused by "they should know better" and these seem like actual functional errors.
I would encourage you to replace this person as soon as possible.
Happy to talk this through in a quick call