Pros
Direct leadership was very supportive and would generally take time out of their schedule to talk through anything. Start up culture allows for opportunities to teach yourself new skills and learn new platforms, so there was a lot of room to grow as an individual contributor if you were interested. Compensation and benefits were decent. Working from home full time added a lot of flexibility and was definitely a nice-to-have.
Cons
I fully understand that there's a degree of pride and accomplishment associated with being one of the "OGs" of a tech company that encounters success, but the rift between the in-group and the out-group created an environment of such hostility that every meeting in one of those circles would border on creating a fight-or-flight response. You'll never be one of them, and they want you to know it. They will promote each other with vague, absurd titles, post pictures of themselves on work trips to Europe on LinkedIn "just bonding as humans, being real with each other, and connecting as a team" shortly after laying off a hundred people without notice. It is remarkably tone deaf and spoils the culture immensely. It is also not uncommon to be publicly called out in a Slack thread at 10 pm with borderline unhinged tirades for the sake of... making an example out of you? Motivating you? The loosey-goosey nature of tech start-ups propagates and legitimizes this behavior, and the only defense strategy exhibited is to try and shift blame. Spectators in these public grilling sessions will privately back you up (often taking the form of "yeah that was messed up" or "that's just how he is"), but will never publicly put their neck out to try and help. The fact that this is even an issue in the workplace is absurd and immature, and a general consensus is that these situations are motivated by stroking the egos of the Chosen Few and reminding you of your place. You will very likely feel like you're not able to trust anyone, and any attempt at speaking out or asking for help will result in someone else's selfish ulterior motive being satisfied with you at the stake. A majority of your in-person bonding sessions will consist of being around unbelievably drunk coworkers, and you're not a good fit with the culture if you don't do the same. Speaking objectively about the work itself, there is unnecessary complexity in its structure. I believe this is a result of short-term solutions becoming permanent structures and "oh, yeah, that's just how it is, here's a workaround" guidance. Processes are not intuitive. You just have to "know how it works." Again, this is normal in start-ups, but employee attrition caused by the toxic environment inhibits concrete, long-term stability. Additionally, the pressure of chasing business deals with tight deadlines and a tech org that vehemently opposes deadlines creates an environment where everyone is mad at each other and significant time is spent salvaging relationships because the juxtaposition in org priorities creates unnecessary tension.