Where do I get market data I can actually trust?
Triangulate. No single source is right on its own. Levels.fyi is strongest for tech and engineering, Payscale and Glassdoor are broader but noisier, and LinkedIn Salary skews toward larger employers. Recruiters who have approached you about comparable roles are often the most accurate source available, and asking them what a role pays costs you nothing.
Weight anything local. A national median is close to meaningless if you are in a market that pays well above or below it.