You'll end up having more trouble hiring when candidates don't want to relocate or leave their current job because it's too risky to join your company which has a reputation to easily fire its employees even though they passed their tests.
If I were unemployed and I wouldn't need to relocate, sure, I'd be willing to give it a try for a few weeks and see if it's a mutual match, that'd be ideal. If I need to relocate or leave my current stable job, you'll have to pay a big premium over my current compensation to make it worth it.
As for easily firing employees, I’m only talking about during a probationary period. And then only for employees who misrepresented their ability to do the job.
There's still the "leave their stable job" problem to solve. I've been in this situation more than once. Do I stay with the company I know: where I'm not getting promotions or raises, but it's a known quantity with a 9-5 work environment, I'm not in perpetual crunch mode, I'm not getting yelled at by a boss as he snorts coke in the conference room. Do I leave this nice stable, boring, no-growth company for yours where they're known to fire fast if they happen to think I misrepresented something? Do I do it for a +10% pay bump? How about for a +50% pay bump?
If we are comparing apples to apples though—same job with an option for 2 interviews, no coding interview, no take home test, but there’s a 90 day probationary period. Versus no probationary period with a 2 month long 7 round interview cycle, I’d take the probationary period in a heartbeat.
You'll end up having more trouble hiring when candidates don't want to relocate or leave their current job because it's too risky to join your company which has a reputation to easily fire its employees even though they passed their tests.
If I were unemployed and I wouldn't need to relocate, sure, I'd be willing to give it a try for a few weeks and see if it's a mutual match, that'd be ideal. If I need to relocate or leave my current stable job, you'll have to pay a big premium over my current compensation to make it worth it.