There are a small group of programmers where I work. A few years ago our boss brought a consultant in to help us move to a newer programming language. Since then our boss was 'resigned' and we now have a new boss. The consultant has recently left and everything he was working on has been divided between the existing developers. This consultant mainly 'worked on his own' while we all sat back wondering what he was doing, he was taking direction only from the boss who is now gone. All of their meetings seemed secret, none of the existing developers had any say or input in any way.
The problem is that none of the existing developers can work on the new code because they do not understand how it works. The consultant was overqualified. His advanced ways of programming has left us in a situation where even most simple requests can not be completed.
We now need to manage this resource internally, but we have not been given the experience or knowledge to do so. How can we manage this issue?