Where to begin...Uber is basically Game of Thrones translated into SV workplace.
No company churns as much as Uber, even at 7,000 employees - the amount of chaos is unnecessary and exhausting, due to inexperienced management and ingrained top-down aggressive culture.
Aggressive jerks and huge self-serving egos are not only tolerated, they are rewarded. You will be instructed to ignore other teams and duplicate effort to reach your goals, regardless of overall value to the company. You will be cursed at, and public ridicule is not punished. Everyone who lasts has sharp elbows and uses them. Many pieces of the Product team are brutally political, with a churn/burn mindset to people. This contributes to a noticeable lack of diversity in gender, race, age, etc. If you don't fit the model of a ex-Google/Facebook late-20's male employee, you won't fit in. Experienced, high-functioning, hard-working and well-liked co-workers "disappear" frequently without explanation or consideration, especially if they don't fit the model. Work/life balance is 24/hour availability because everyone is drinking the Kool-Aid.
Pay is intentionally below market - Uber tries to take advantage of its stakeholders whenever it can, because this company does not value individuals. If you can get a competing offer during interviews, THEN they will raise your below-market salary offer - but not before.
Many inexperienced employees think they are good, but in reality they are just lucky due to the perfect timing of product-market fit.
Because Uber's equity policies are anti-employee, there are many people who are "friends of management" and grandfathered into the organization but can't afford to leave, even if they want to. Once this thing goes public, everyone will cash out and leave - nobody wants to work with a bunch of jerks.