The big ones: dot-com bust (2001-2003) saw ~560k tech jobs lost per BLS, took until roughly 2007 to recover. 2008 financial crisis hit tech less hard but still significant layoffs. Then 2022-2023 saw ~260k+ layoffs tracked by layoffs.fyi, mostly at companies that had massively overhired during the ZIRP/COVID era. The current cycle feels like a continuation of that 2022-2023 correction more than a new event - hiring never really bounced back the way it did after previous downturns.