Pros
Pay is competitive and benefits are generous. Friday booze (if that's your jam). Equity is generous and looks like it'll be worth something soon.
Cons
Worst presence and execution of in office politics of any office I've ever worked at. It's not that things are overtly political and tedious, but that people don't even know how to be political effectively. It's sort of embarrassing. Slowest moving tech company I've ever worked at. The amount of hoops that you have to jump through are similar to large, old companies. Death by Power Point. Clandestine culture that's also poorly executed. People try to do a lot of work in the dark and change org structures in secret, but the secret always gets out, people always get nervous, and the execution is just horrific. Management is generally weak (although there are good individual contributors). Lots of people who were good ICs and just happened to be old timers end up in leadership roles even though they are really bad leaders. This is pretty prevalent in marketing, analytics, operations, and product. Think of large company process and progress with start up chaos. Tools are weak. Inability to focus on most important problems. For 60% of the teams at Lyft, I could not ever recommend joining.