FWIW, 20% time was always controversial. I was part of 'the surge' (a big hiring wave that peaked in 2006 and then died off) and a common complaint was the low number employees had 100% time (they could work on what ever they wanted) and high number employees had to get their manager's approval, and their manager only approved it if it was something the manager needed doing.
Given the nature of that particular 'perk' it was really hard to quantify it for the employee handbook. I came to believe that it was a sort of test, kind of like the tests in Starship Troopers where if you did something that clearly was going to be a Google product or feature then you got points for that, but if nobody could figure out what use it would be, you got penalized. And the option was like either +1 point or -10 demerits (i.e. very unbalanced).
So over my four years the strictures on what was or wasn't 'acceptable use' of your 20% time got more and more constrained. I wouldn't be surprised in the slightest if the language had morphed into 'if your really a star performer we'll let you pick your next project' rather than the oft misunderstood 20% to do whatever you want.
Right. If you're above the Real Googler Line, then not only do you have 20% time, but no one's going to stop you from spending 100% of your time on your 20%T project... it will delay your promotion if your 20%T project isn't successful, but that's all. Real Googlers don't sweat Perf or worry about getting fired. They only pay attention to managerial demands when life events (such as having a kid) increase their expenses and they could really use a promotion this year. Otherwise, they do whatever they want.
If you're below the Real Googler Line, and most new hires are, your 20%T project is your 80%T project: appease your manager. Nothing else matters, not "performance" in the abstract or doing something great for the company. Forget all those distractions. If you're below the RGL, your job is to please your boss and serve his career goals. "Peer review" won't protect you, either, if you're at a lower level, because no one below Staff is taken seriously as a peer reviewer. (Remember, they aren't Real Googlers.)
The whole story around "Google culture" is based on what Google is like for people above the RGL, but it takes several years to get there, and it's next to impossible if you're not at one of the top 3 or 4 campuses.
The Real Googler Line used to be at the Senior rank, but now it seems to be closer to Staff (and some Staff SWEs seem to be below the RGL). That means that if you come in at the SWE 3 level, you're two promotions away from it, in a company where the average promote rate is about 10-15% per year. Unless you have a star manager who gets his reports promoted like butter, you're wasting your time.
Google needed to grow a pair and fight to protect its culture from all these transplant executives who brought in terrible ideas from other companies with shit cultures. It needed to man the fuck up and make open allocation an official, unassailable plank of the culture. Now it's too late.
Google still has 20% time, in the aggregate. About 20% of engineers are Real Googlers and get to work on whatever they want, 100% of the time. The other 80% have one job: appease your manager, because your manager is a SPOF for your whole career. In other words, it's no different from a typical dysfunctional corporation.
Google claims to be a "peer review" driven company, but if you're below the RGL, then the odds are that your peers are too, and then they have no clout and can't protect you from a priapic manager looking to get some bad Perf on.
Senior SWE is the traditional Real Googler Line, but now it's closer to the Staff rank.
