It's really not obvious to calculate the output of any employee even with years of data, way harder for a software engineer or any other job with that many facets. If you've found a proven and reliable way evaluate someone in the first 2 weeks you just solved one of the biggest HR problems ever.
What if, and hear me out, we asked the people a new employee has been onboarding with? I know, trusting people to make a fair judgment lacks the ass-covering desired by most legal departments but actually listening to the people who have to work with a new hire is an idea so crazy it might just work.
