Pros
Credit Karma pays well. Benefits are pretty good too. If you have a good manager, you'll be fine. I had some really excellent managers while at CK, but they had to deal with some very silly policies from people above them. Work/life balance can be good if you push for it.
Cons
Leadership and company lack direction. They haven't really been an innovative force in a while. As an individual contributor, this means that the work you're doing often doesn't feel particularly important or interesting. The Intuit acquisition really shows how far CK drifted from its original mission to help regular people. CK leadership has 100% bought into the Intuit company line on making taxes complicated is better for individuals, even though no other developed country in the world makes it so difficult or expensive for people to pay their taxes. Not a particularly diverse place, and it didn't really improve over time. I saw some real lack of empathy as a result. There hasn't really been a lot of investment in DEI. Sometimes it seems like leadership is completely divorced from the people who actually make things at their company. That means that sometimes you'll get sent on a wild goose chase because someone 4 or 5 levels up has no idea how products or partnerships actually work and the people below them don't feel empowered to push back.