This question's hopefully less close-able cousin.
What steps can I take to avoid having future potential employers take a position of high responsibility less seriously because I reached it quickly? Quickly meaning in less than a year, and high responsibility meaning beyond the scope of the job at many similar organizations.
I work in the legal industry. My situation (without going into too many specifics) is that I have been given a lot of responsibility at my current workplace and perform many tasks that would ordinarily fall to someone with a specialized degree. I am expecting to stay here for a year or two in total before moving to a different city. This kind of turnover is not unusual in my organization, and is even encouraged, but I know that's very much not the case at most other similar institutions.
I'm concerned that the short amount of time I'll have worked this job will end up devaluing the experience I have gained and that my successes here will appear less legitimate to potential employers going forward. How can I avoid this (either by language I can use in my resume/cover letter or things I can say in an interview)?