Author here. We sell mock interviews at interviewing.io, in the styles of specific companies. Sales data lets us see what's popular, which in turn, let's us gauge how much hiring is happening there.

Our sales data has lined up with previous events like hiring freezes and hiring booms (e.g., when Amazon briefly when on a hiring spree after Google and Meta froze in 2022). You can see more historical data here: https://interviewing.io/blog/when-is-hiring-coming-back-pred...