you should not be working on same project or same company in IT for more than 3 years. It has been researched and specially true in IT. It's really bad for your career and your mind. I was in your shoe before and began to feel bored after 3 years in same project. After I changed the job I am again happy now. But don't change the job just because you are bored. Weigh different option like salary, work life balance etc. But you will hit the ceiling soon as you grow and then you will be more involved toward management rather than coding.