As of 2020, I have worked at five startups. I am writing this to give some insights about working in startups.
Compensation
Stock options are commonly part of the compensation package as startups are generally unable to pay the market rate. Pay raise is dependent on the company, while a bonus is rare.
I think stock options are overrated. Firstly, it's hard to get clear insights about stock options' value. Second, stock options are more complicated than shares. Some taxes and terms are not beginner-friendly.
Nowadays, I appreciate the straightforwardness of bonuses. You can always use your bonus to invest in early-stage startups if you are a risk-taking person.
Career Progression
Based on my experience, promotion is subjective. I have seen people getting promoted twice in four months and seen people who don't get promoted at all.
Startups' titles, in general, are inflated as some startups are unable to give an attractive compensation package, so promotion is the way to incentivize people. I have seen a team leader without anyone to lead.
Skills
I buy the fact that a startup gives you accelerated learning. You have to pick up new skills and deliver results fast to meet the impossible deadline. In short, you are forced to grow.
Impact
I can see how much work impacts the startup. I can rewrite the codebase, and rebuild the database or API if it's easier for me to rebuild than refactor the code. This flexibility is a plus.
However, a startup serves a small pool of customers, so this impact is mostly overrated.
Network
My roles at these startups are mainly technical. I spend more time coding and talking to the machine than to humans (customer/user). Since I join early-stage startups (< 20 employees), I only interact with a few people daily. I do not get to know new people.
Working at startups means that you often have to work crazy hours and deliver results in the shortest possible time. By the time I finish work every day, I barely have any energy left to go to social events. I do spend time to workout since it helps me destress and sleep better at night.
I don't know if I will get to know more people if I work in a corporate.
Work-life Balance
In general, there is no work-life balance. You are expected to work hard and long hours even if you are poorly compensated.
Conclusion
In general, I wouldn't recommend people to join startups. The risk is too high.
I haven't found an early-stage startup that has the potential to become the next Google, even though I think I am well-versed in the startup industry.