
P50 goals address sandbagging. If you achieve all of your goals, you receive a demerit on your review. Achieving none of your goals is also bad. The best possible result is a new goal, more valuable than any of the predicted goals, that was discovered and satisfied during the review cycle.
…omeone reaches L7 or so, it’s expected that they have an essentially complete mastery of technique. The truly hard parts about this job are knowing which code to write, building the clear plan of what has to be done in order to achieve which goal, and building the consensus required to make that happen.
And once you’ve understood the system, and worked out what has to be built, do you retreat to a cave and start writing code? If you’re a hobbyist, yes. If you’re a professional, especially one working on systems that can use terms like “planet-scale” and “carrier-class” without the slightest exaggeration, then you’ll quickly find that the large bulk of your job is about coordinating and cooperating with other groups. It’s about making sure you’re all building one system, instead of twenty different ones; about making sure that dependencies and risks are managed, about designing the right modularity boundaries that make it easy to continue to innovate in the future, about preemptively managing the sorts of dangers that teams like SRE, Security, Privacy, and Abuse are the experts in catching before they turn your project into rubble.