If the goal were to minimize the number of false positives, I would agree. But the managers of these teams had enough experience to know that they'd rather hire one person a month for a year and only keep one gem than to spend days or weeks trying to find that one gem and then agonize over firing them (knowing that the hiring process is slow and expensive) when the gem loses its shine.

Having done a fair bit of hiring myself, I can't even begin to reliably identify gems. If you know of a way or can explain how multiple rounds of interviews can do a reliable job of identifying them, I'm all ears. I can tell the stinkers right away I think, but gems, no that's really hard. The best candidates I've interviewed (resumes, work experience, knowledge testing, etc.) haven't had any better luck becoming great team members than those with a mediocre interviewing quality.

Cause here's the thing about gems: They only work within their setting and can be created, with some effort and skill, right out of raw material.

I disagree with what your idea of proper hiring apparently is; to hire and test out a lot of people often is better than to spend extra time finding the right person. In my experience, a work environment that is a revolving door of often failing new staff is a waste of everybody's time, whereas a work environment with more carefully selected new staff that sometimes fails is only a waste of management's time. Such are the burdens of management.

I agree. This sounds like bad/lazy management, and a broken on-boarding process.

As a consultant, I've grown used to working around bad on-boarding processes but most FTEs aren't used to jumping into existing teams without being given a lot of knowledge. I can imagine tons of great people washing out of such a team not for any good reason but just because they aren't used to self-service on-boarding.

This may depend on the specific job. In sales I could see this with some correct period.

Sales has its own high-risk / high-reward culture that goes along with the people who hunger for it as a career. Since most sales positions are paid on commission, failure to meet sales goals tends to result in a firing.

In my experience salespeople do need some ramp-up time (although it depends on inside/outside, size of sale, etc.), so 30 days may not be reasonable.

Commission vs. base actually argues for letting them stay LONGER. They self-select to leave if not making commission -- at a startup, that could be due to the product not being in the right place, though, so in a startup you often pay more base than at an established provider.

The other issue is that the cost of a "seat" for a salesperson, especially outside, can be really high, independent of production. It's pretty reasonable in enterprise for a great salesperson to be burning $500-1000/day in expenses (flying every couple of days, hotels, cars, meals with clients, etc.). Plus, potentially needing a sales engineer or engineering support from the development team, and of course the opportunity cost of giving them certain sales leads ("these leads are shit! give me the Glengarry leads!").

Enterprise sales is one of the reasons it sucks to do an Enterprise startup.

I don't think interviews, even with technical components, can tell you even with 75% certainty how a candidate is going to perform at the actual job. There are considerations like work ethic and how well someone can grok the actual issues the company faces (as opposed to a toy problem) that you just can't really know until they're actually doing the work (or not). Some people are really smart but turn out to be lazy. How do you weed them out in an interview?