Development: Code Review
A Code Reviewer is somebody who looks on the source code, checks it for correctness and thinks about optimizations.
Nobody is perfect, we are human too. Even today then and when a bug shows up we did not recognized before. The only way to make the linux-dvb code as stable and robust as possible is that as many developers as possible analyze the source and watch out for potential bugs and weaknesses.
When you get a nice idea how to make things better or to introduce Performance Optimisations then please start a thread on the linux-dvb Mailing List and let's discuss it.
As soon you encounter a point where you see that it would make sense to rewrite portions of the code, to get into a deeper refactoring process, please have a look into the Hints for Refactoring existing DVB drivers section in this Wiki.