The biggest problem I've seen that keeps code from becoming simple is the fear of deleting it. Instead of understanding what a piece of code does and whether it

The biggest problem I've seen that keeps code from becoming simple is the fear of deleting it. Instead of understanding what a piece of code does and whether it could be pruned, people opt to extend it instead. Another one is bad/thoughtless interface design; everything you add to a codebase can become a dependency for some other part, so give at least a minute or two of thought towards what the interface is and how widely it's exposed. If it's local, it matters less than some core abstraction used everywhere.