[soulchild77]

Never, when it felt right. I'm in my mid fourties now, still doing web development and I stayed 13 years at a startup and am now celebrating 10 years at my current employer. In between I joined a somewhat well-known (prestigious) company which had a very toxic work culture, so it was a no-brainer to leave after just 1,5 years. Management was clueless, most people were awkward all the time, pay was very good, but I just couldn't stand going to work.

If the company values your work (not just by giving you an appropriate salary, but also acknowledging that you're a valuable asset and not just arbitrarily replaceable), gives you enough freedom and your colleagues are cooperative and nice to work with, why leave? You probably wouldn't leave your partner just because you've been together for a too long time, would you? ;-)

[Cheezmeister]

How did you find weathering the growing pains, as your first employer (presumably) went through startup adolescence? Did you remain IC or branch into people-management?

Sound advice, caveat that (for so many reasons) a shop that feels right and _stays that way_ is increasingly rare and precious.