Levels.fyi started off with a very simple mission - to anonymously share verified compensation information for s/w engineering roles in the US. It’s still pretty much doing just that only now with much larger dataset, up and down seniority levels which it has help standardise in product tech companies and across all roles in tech startup / scale up. This is all just data, in a simple interactive website, refreshing free of analysis. Must read of course, especially for tech recruiters.