Well, there are a lot of old problems to solve as well, but in general productive developers develop proficiency at using established solutions to them. There

Well, there are a lot of old problems to solve as well, but in general productive developers develop proficiency at using established solutions to them. There is a real skill in being able to find a solution to a similar problem and convert it to fit the new problem as well as being able to break a new large problem down to a number of small old solved problems a few new small problems.