I have 10 years of experience in the field, I'm based in Silicon Valley. Worked in the city, south bay and the peninsula. I'm a full stack engineer, I switched employers 7 times in 10 years constantly getting pulled into another hot opportunity! Sometimes from ex-colleagues, most of the times from recruiters. Looking at glassdoor.com and my personal experience, salaries are much lower than what people are claiming on HN. There are exceptions out there, Google, etc. I've been their myself as well as another one of the big 5. Experienced engineers make a lot of money but it's mostly coming from Stock/RSU's and sometimes bonuses. I'd totally believe it if you tell me "my total offer was about $300-500/k", but it's not yearly. And the base salary is rarely $200k/year for a "simple" individual contributor. Unless you're a guru at google. It seems that a lot of guru's at google are active on HN :) Most of it comes from RSU's or stocks cumulated after several years (or well negotiated when hired). The vesting period is usually 4 years, not one year, so you can't really say my package is $500k. It doesn't mean anything. I would say, the base salary for 10 years of exp in Web/Mobile or any related field is about $140-$170k per year on average. After tax it's obviously way lower.
A lot (too many) people on HN are claiming $200k base salary per year as being totally normal. I honestly wish it would be true!!