Let me add just one specific criterion / thought:
Move on when people stop listening to you.
You joined the company because you thought it was a good fit, that you could grow and make an impact.
After a while, it often starts to not feel “right”. Things change. Should you stick it out? Try to fix things? Work harder?
We often make the wrong decisions here in startups. We often quit just when it’s getting good — because in startups, that’s often just when it gets hard.
So check your gut. Your gut may actually be wrong here in a fast-growing startup. Fast-growing startups have tons of change and make tons of mistakes, and that creates confusion and “uncomfortableness”. But those are bad reasons to quit. If you want stability, go join a mature Tech Company growing 15% or more year over year. If that’s your thing.
Instead of quitting, ask yourself one basic question — do people listen to me?
If they do, you are respected, and have an important role. If the startup is objectively a good one, and growing quickly … maybe stay at least a little longer. You have the respect of your team and peers and boss in an important company. You can make an impact. You matter. That’s less common than people think.
But if people no longer listen to you … well something has changed. You may have lost the respect of your team. Maybe your boss isn’t a great boss. Maybe it’s your fault. It doesn’t matter.
See if you can quickly fix this. But if not — it’s time to move on. There’s no longer any growth opportunity for you there.