I've always struggled with this topic. Depending on the client, it's near to impossible to set a retainer. But those clients are the ones that after deliver, expect a "perfect" product, free of bugs. And bugs always appear, one after another, eventually, forever.
So I wonder which policies are you talking regarding these topics?
I know some people apply the harshest: After delivery, no bugs fixing without quotation. Some others have told me they have a warranty period. There is one guy that provided a 10-year warranty period which is kind of nuts for me. #dev #programming #technology