Here’s a braindump of some things I’ve learned over the years. Caveat lector: my experiences inform this, and they aren’t representative of all the possibilities, etc. Ignore this if you want; I’ve been meaning to write some notes for Kiwis or Aussies who are joining startups for the first time, and someone just became my excuse.
Maturity
Startups are very immature organisations, unlike a corporate or university – I always describe it as “there’s more work to do than there are people to do it”. So there’s huge opportunity to do stuff you wouldn’t ordinarily do, which is great. There’s also a lot less support, which can be unnerving. There’s nothing preventing you from working super-long hours and burning out, and only your coworkers to notice (HR is almost non-existent in very early stage startups). And even compensation is weird (“stock options”?) and can bite you if you’re not prepared.