A 50th percentile base salary for a senior engineer in the Bay Area is around $150k-$160k per year. Most companies offer a cash bonus (10%-15% of base); including this puts a typical cash compensation total for a 50th percentile senior engineer is between $165k and $184k per year. Most companies offer stock, but the grant and value of these varies wildly. Public companies' stock is actually worth something but you have your places like Google where RSU grants are a huge portion of salary and other places where it's closer to the cash bonus portion of salary.

This is all gross, pre-deduction salary; not salary net of taxes, deductions, etc.