The problem of a probationary period is that it pushes all the risk to the employee.

While I agree interviewing has gotten ridiculous with all the leetcoding and ten rounds of interviews and FAANG cargo-culting and whatnot, one small advantage - assuming I'm not desperate for a paycheck - is that it gives me, as a prospective employee, time to consider and withdraw my application if I see too many red flags or I just prefer the devil I know.

A short interview process with a probation period on the other hand is a big roll of the dice. Maybe I'm not able to ramp up on time, or make a silly mistake due to unfamiliarity with the codebase or underlying business logic. Maybe I don't get on with the team or manager. Maybe I'm going to be dumped into a doomed death march project on day 1. I could find myself unemployed a month later with an embarrassing gap in the resume. Perhaps on the other hand a better interview process (not longer, just have properly trained people and constantly improve the process with feedback) would save us all that pain.

In a world where short, high-risk interviews dominated, you could just go roll the dice again. It would be a negative signal (why is @foo interviewing after only 60 days?), but nowhere near as bad as “why is @foo still interviewing after 6 months in this job market?!”.

Contacts in what sense?

Probationary periods could work but it's a coordination problem. Such periods are the norm in Europe (coz it's very hard to fire someone) but for an at-will place like the US, given that the industry doesn't really do probationary periods in general, any employer who starts doing it would be at a disadvantage.

*contracts

In the sense of offering signing bonuses for term lengths that get repo’d if the contract length is broken.

I think GP meant "reference check"

I meant “contract” but you’ve brought up another good idea.