How long does it take for a software engineer to get promoted from L3 to L4 on average?
Does it take less time if you come in with previous experience?
Not usually but I'm sure some goofy fuck will swing by to say they did it in 3 months or whatever so I guess anything is possible. Expect them to draw it out as long as they can.
It should. Most of the time people joining need to ramp up on the Google tooling and codebase. However, I fully expect someone experienced to be able to level up to L4 within a year. 6 months is hard because you must have launched something.
2 years