There’s a whole class of bugs that comes down to the developer followed very specific instructions without understanding the goal. And a well-meaning manager will take that to mean I wasn’t specific enough in my instructions. No! Computers need instructions. Humans need understanding.
I like to take developers with me when visiting customers. A common understanding of the goal removes so much friction and makes life so much easier.
I also recommend Basecamp’s Shape up to break down the barrier between product and IT and have small teams work closely together to ship a new product or feature.