Here is total employment for "Computer Systems Design and Related Services" going back all the way to 1987. This is the best category I can find that includes data over a decade+ time frame.
This category is defined by the BLS as "establishments primarily engaged in providing expertise in the field of information technologies through one or more of the following activities: (1) writing, modifying, testing, and supporting software to meet the needs of a particular customer; (2) planning and designing computer systems that integrate computer hardware, software, and communication technologies; (3) on-site management and operation of clients' computer systems and/or data processing facilities; and (4) other professional and technical computer related advice and services."
Here is total employment for "Computer Systems Design and Related Services" going back all the way to 1987. This is the best category I can find that includes data over a decade+ time frame.
https://fred.stlouisfed.org/series/IPUMN54151W200000000
This category is defined by the BLS as "establishments primarily engaged in providing expertise in the field of information technologies through one or more of the following activities: (1) writing, modifying, testing, and supporting software to meet the needs of a particular customer; (2) planning and designing computer systems that integrate computer hardware, software, and communication technologies; (3) on-site management and operation of clients' computer systems and/or data processing facilities; and (4) other professional and technical computer related advice and services."
Yeah, using 2020 as a baseline for most industries is fine, but in the case of software the anomalous job market really started by 2014.