The new technology that interests you. Seriously, several of the technologies emerging now are likely to be big (or at least grow substantially) over the next

The new technology that interests you. Seriously, several of the technologies emerging now are likely to be big (or at least grow substantially) over the next few years. But if you focus on the one you find most interesting it will help keep you focused and motivated which can be an enormous help. It will also help you enjoy what you are doing which simply makes the process more pleasant.