It's hard to get a complete picture of the situation from this little vignette, but your wife might be on to something. There's a difference between "intense"

It's hard to get a complete picture of the situation from this little vignette, but your wife might be on to something. There's a difference between "intense" and "toxic". Firing 2 people in 3 months may be a sign of a toxic environment. Leaving _two_ yelling, swearing voice-mails may be another. It's OK to be upset about missed deadlines or unmet responsibilities. It's not really OK to yell and curse at your staff because of it. Part of being a professional (part of being an adult for that matter) is being able to act in a manner that is different than how you feel. Verbally abusing the people you work with isn't "intense", it's at best rude, and shouldn't be accepted as par for the course. I'm not saying the CTO is necessarily a bad guy because of this. We all lose control of our emotions at times. But let's be clear, this really isn't acceptable workplace behavior, startup or not. If it happens often, I'd take that as a very bad sign. And this is more than a question of a toxic work environment (although frankly that may be reason enough to quit). It's really a matter of the success of the business. If the founders/management team aren't able to act professionally with their staff, how will they handle disappointment with investors, clients, partners? It is likely that if this is a problem it will manifest itself in more places than staff relationships. (BTW, Do you have "stock" or "stock options"? Has your stock vested? If options, how likely are they to turn into anything real? If you've got a real stake in the business, that's great, but otherwise working 14+ hour days 6 days a week on a regular basis might also be a bad sign. I've witnessed this more than once with people I know: the founders don't offer early, key employees any significant stake in the business but still expect them to have 18-hours-a-day, 6-days-a-week dedication and drive because, you know, "it's a startup". Founders: If you're not giving your staff a vested interest in the business, don't expect them to be as engaged as you are. It's just not rational)