How is it not? How does anyone join a company and make any significant contributions in less than 2 years? How do you even become a leader within a company in less than two years? You just throw out all the relationships you have built every 2 years? It is a red flag.
I spent 18 months in my first post-PhD job and in that time I drove consolidation of all of the tests (code base has acquired 6 frameworks over 20 years) into a single framework and got people actually writing new tests. I fixed parallel building which brought down the clean build time from 3 hours to 15 minutes. I did the work for a feature which was used as the major marketing selling point in that year. I got a very decent pay rise and bonus because of these things before I left.
