One interesting question that isn't really addressed in the article or the comments here is what advice applies to folks who don't really want to move beyond the staff engineer (IC track) or senior manager (management track) level. I have not heard of anyone getting penalized at the staff level for short stints; though I do agree with the gist of this comment and article at the principal engineer (IC) or director (management) levels.

Companies across the industry are well known and notorious for having 4 year cliffs. HR often has no interest in keeping a good senior/staff level developer. Furthermore, companies are also known for making subsequent promotions harder than the first and are more than happy to let developers stagnate - managers at most companies are not responsible for providing growth opportunities beyond the so called "terminal levels" which is roughly senior/staff at most places.

The easiest way for many to keep learning, keep compensation in line with the market, and continue working on interesting projects is to simply hop for a new opportunity after a few years; cliff just makes the choice easier most of the time.

At least from what I have seen, one has to be really fortunate to have good managers/leaders (who can help with some of these issues) and/or a company which aligns very well with one's own goals over a long period of time. I don't believe either of these are common.