How to choose between FAANG vs pre-IPO company (different roles)?

The dimensions to think along here are: 1) learning 2) future prospects and 3) compensation. But not necessarily in this order though as you may have your own priorities.

Learning: You'll likely wear many more hats at the startup than at FAANG. See my detailed answer on this here.

Future prospects: You'll likely be better positioned for your next role given the breadth and depth you'll gain at the startup. Even if you're in a fullstack role, you'll likely need to dabble in multiple areas to get your task done and maintain your system.

• By better positioned, I mean showing up as a more seasoned engineer at the role after that. But it may not translate into the next title up. For example, another startup or mid-size company might be willing to level you at Staff, but FAANG or another bigger company might offer only Senior.
• If you don't work at scale at the startup, that might be a detriment in interviewing next time around. Some bigger/ambitious companies value prior scalability experience.

Compensation: Given that startup equity is uncertain (and pre-IPO equity is more uncertain than acquisition equity), this is something you'd have to consider for yourself. I generally see the startup equity as "bonus," so I mostly factor cash comp in my decision.

I know many people who have built an entire career working at startups and many others who bounce from FAANG to FAANG. Yet others have had mixed careers. So, there's no right or wrong answer here.

If you're having a really hard time deciding, consider this: the FAANG job will always be there whereas the startup may be a less frequent opportunity given the combination of their domain, your role, and the company stage.

Hope this helps.

It's tricky without knowing names, but I'm at least 80% sure you should take the pre-IPO offer. Pre-IPO unicorns are a great balance between having stability (the company won't die within the next 2 days) and opportunity for growth (compensation growth, skills growth). FAANG is overwhelmingly biased towards stability and growth is really rough due to lack of scope - The stability angle has also been challenged recently with all the layoffs.

The FAANG company also gave you mid-level instead of senior, so this seems like a pretty easy decision to me. You will most likely make more money, have more scope, grow faster, and have more fun at the pre-IPO.

Best of luck with the new job!