Go for this Job then stay for about a year or so. I expect that even though they are early stage they will hire only if they have 1year cash reserve to support it because they plan for series A soon.
I don’t expect them to have 2nd year cash reserve given that it’s bootstrapped and are paying such high salaries. They are probably relying on Series A or profitability( which seems far fetched this early).
But it is safe to say you can stay there for a year. If things go south you can always excuse that you believe in the mission and learned a lot and was required to take charge of work frequently. Basically sell the next employer on what all you learned in this highly unstable role where the startup could shut down and workforce was also lean to begin with.
Companies appreciate if you are early engineer in a startup or have tried one yourself. It really polished your resume. There are over 50k workforce EACH in Google, Meta, MSFT, etc all over the world working in FAANG. You can go there anytime, more the experience the better it is.