That would make switching jobs really hard, effectively making the interview process three months long. Only now, candidates have to quit their current job before they can interview, and if the first "contract" doesn't end in a job offer, the candidate no longer has a job.

Then you just set up your business so 90% of your company is filled with said 3-month workers at minimum wages.

There’ll be no shortages of applicants for quite some time but really destroys the society. So no.

No unless I’m guaranteed that upper echelon slot to judge them — no I wouldn’t want to live in a society like that.

If I employed fulltime now, then I'm unlikely to consider switching to 3 months contract.

On the other hand, I think it may be a good idea for the company to consider:

- either hire fulltime somebody, who has solid track record and "prooved" themself during on interview

OR

- offer 3 months contract to someone, who is not that good at passing interviews, so they can prove themself doing real work.

That would be fine for new college graduates and other unemployed developers, not so well at attracting talent that already has steady employment.

If you have a steady job, then there may not be as much social utility in optimizing things for your situation.