Ex-Google SWE L5 (Senior) - Left in 2014 after almost 9 years spanning from my late 20's to mid 30's.
I really can't complain, and would easily rank it as my most fulfilling and lucrative full-time employment experience so far, though the previous and post employment were in defense and startups.
In short, I left due to burnout, though I think it wasn't so much the team/work as it was my character lends itself to burnout if I'm not very careful to erect work/life barriers and not trample them in spite of myself. I also tried hard but failed to get promotion to L6 SWE, and that left me with a bad taste in my mouth. This was mostly a matter of personal immaturity at the time though. In retrospect my technical skills may have passed muster, but my ability to make things happen in the organizational and interpersonal sphere weren't really at an L6 level. My foot was already half out of the door by then, anyway.
In the intervening time, I've worked on an (unsuccessful) Android game, worked at a startup (again, burnout is easy when you internalize the existential precariousness of this sort of venture), and have since moved back to my hometown, bought a nice house, started a family, and done remote contract work. I have a few projects incubating and am planning on pursuing some entrepreneurial bootstrapping once my current contracts peter out shortly.
I miss the proximity to amazing engineers and casual availability of supercomputing resources, but in the end, I'm grateful to have saved enough to have a great deal of freedom in how I spend my days and to have been fully present for the first few months of my son's life.
Another benefit of time outside of Google is getting acquainted with the equivalent software ecosystem outside of their walled garden. Borg -> Docker/Kubernetes, MapReduce/Millwheel -> Spark, Dremel/bigquery-> Presto, etc etc.
L5 is one of Google's internal levels. They're putting it there to let people know where they were in Google's hierarchy and they note that it denotes Senior. From what I know, people generally start at 3 right out of school.
To expand a little bit, you usually start at L3 as a fresh graduate, and then are expected to be promoted to L4 within ~2-3 years, and then L5 after another 2-3 years (although it could be shorter). L5 is considered a "terminal" position, in the sense that once you get to that level you're no longer expected to get promoted. (L3 and L4 are, by contrast, more "up or out", where if you don't get promoted after long enough you can get fired.) I actually met an L5 engineer at Google who had been there since 2002. Promotions to L6, L7, etc. start to get exponentially more difficult.
In short, I left due to burnout, though I think it wasn't so much the team/work as it was my character lends itself to burnout if I'm not very careful to erect work/life barriers and not trample them in spite of myself. I also tried hard but failed to get promotion to L6 SWE, and that left me with a bad taste in my mouth. This was mostly a matter of personal immaturity at the time though. In retrospect my technical skills may have passed muster, but my ability to make things happen in the organizational and interpersonal sphere weren't really at an L6 level. My foot was already half out of the door by then, anyway.
In the intervening time, I've worked on an (unsuccessful) Android game, worked at a startup (again, burnout is easy when you internalize the existential precariousness of this sort of venture), and have since moved back to my hometown, bought a nice house, started a family, and done remote contract work. I have a few projects incubating and am planning on pursuing some entrepreneurial bootstrapping once my current contracts peter out shortly.
I miss the proximity to amazing engineers and casual availability of supercomputing resources, but in the end, I'm grateful to have saved enough to have a great deal of freedom in how I spend my days and to have been fully present for the first few months of my son's life.
Another benefit of time outside of Google is getting acquainted with the equivalent software ecosystem outside of their walled garden. Borg -> Docker/Kubernetes, MapReduce/Millwheel -> Spark, Dremel/bigquery-> Presto, etc etc.