As a former recruiter. The I.T Sector is probably the most flexible and dynamic than any other, with a large percentage of developers working as contractors (applies particularly to the UK & USA).
This is partly due to many software houses working on a project by project basis therefore only recruit staff on the basis of their business/project needs.
In your case I would assume you are working predominantly a permanent roles. Rather than thinking about the number of years think about what skills you are learning. For example if within a 1 year you feel that you’ve learnt all skills experiences that you need to take you to the next level! Start applying for jobs.
In the same vain if you find you are getting all the skills, excitement, challenge that motivates and you look forward to going to work the next morning. Then stick to it even if it’s 5 years +.
At the end of the day base your move on 3 key factors.
- Is this job improving my skills and exposing me to the latest technologies that will make me a valuable in the job market.
- Am I enjoying my job and feel motivated?
- Am I being being paid the market rate?