I work at Uber since 2017. There was a noticeable shift in priorities in the company related to efficiency and profitability (whereas before the IPO there was a lot of pie-in-the-sky stuff going on)
For me personally, there wasn't that noticeable of a difference in terms of career trajectory - my entire role is about creating efficiencies and I feel that my career would have progressed as it did regardless of IPO - but I saw other teams being negatively impacted. Many people were laid off in 2019 as a result of efficiency seeking initiatives from the leadership team, and others left as the company shed unprofitable verticals (e-mobility, and more recently self driving and aviation), and there were numerous structural changes internally as well.
In terms of career, IMHO the changes brought a lot of incidental opportunities to grow in terms of breadth of technical knowledge, but in a go-get-them-yourself sort of way, not so much mandated from the top.