It's a way to correct under-leveling rapidly. Google at least aimed to hire at the level of fully demonstrated and sustainable competency; if there was any dou

It's a way to correct under-leveling rapidly. Google at least aimed to hire at the level of fully demonstrated and sustainable competency; if there was any doubt you'd be hired at the lower level. That can be corrected in a ~year with greatly exceeds or redefines ratings. There was a bit of step function in yearly raises depending on the rating as well but promotion was a substantial raise.