Comment by danieltillett

I write scientific code for a living and my code is very difficult for anyone else to maintain. It is not because my code is badly documented or written, it is because what it does is very complex. Every module is documented why it exists and what it does and the code straightforward to read, yet the interaction of all the modules is very complex as it reflects the underlying complexity of the problem the code is solving. Some code is hard to maintain because it is solving a complex problem that few people understand.