How to find missing data

Spreadsheet 1 is a list of employees, their job l, and their current certifications.

Spreadsheet 2 is a list of all jobs and what certification is required on that job.

I need to find what certifications the employee is missing based on the requirements of their job. I can’t think of a way to look up since it’s many to many. So far I’ve added a helper column of Job/Cert to both spreadsheets but not sure where to do from there.