Lots of opportunity to grow and learn in the company. Was able to level up career substantially due to the amount of scrappiness all around. A lot of roles and positions are created as needed, so there's plenty of space to grow.
Also, great people all around. Sometimes petty, but generally all very well meaning.
Cons
Main con is that a lot of people aren't direct and projects get stalled due to indecision. Some passive aggressiveness, but not enough to create a toxic environment.
This unfortunately also extends to company goal setting, etc. Due to the indecisiveness, there can sometimes be a lack of clarity in direction.
Lyft has a reputation as a "nice" company, and the people live up to it. People here believe strongly in the mission of the company and they're really smart, but the egos aren't out of control. The company moves quickly, so it's exciting to see your work have an impact. And the benefits are pretty good: free Lyft credits, catered lunch, amazing maternity/paternity leave, dogs at the office.
Cons
The compensation is a bit worse than you'd get elsewhere. (Wait, no 401k match?) So you're definitely sacrificing a bit for the privilege of working at Lyft. And the flip side of the fast pace is that objectives change a lot and cause thrash.