Unfortunately that's not enough to guarantee success. Even the most well run company can still fail to find product market fit, just be at the wrong time, or just get screwed over by external factors or even other internal factors. Conversely, a poorly run company with a toxic culture can succeed despite problems a rank and file employee might see.
If you've joined unicorn X pre-IPO, you've hopefully got a decent amount of pre-IPO options, at which point might I suggest diversifying in case the market doesn't share your confidence in the company.
I am not advocating IPO trading.
I am saying join unicorn X, see of they have a good plan, if the company is well run etc.
You can tell because you are working there. Then if it is a good buy buy it, otherwise don't.
It is a bit like a hunter "tracking" their deer for 2 days rather than walking around shaking trees.