Don't put a ring on it - just yet, anyway.
I recently received a request for advice that read “Many candidates either interview well or give the impression that they have a strong background - but turn out to be a bad fit culturally or end up being a toxic member of the team. How can HR and hiring managers identify poor-fitting/toxic candidates during the interviewing process”. In other words, “How can we mitigate the potential for a 'messy divorce’?”
You most likely can’t - but there is an approach that can minimize the fall out
Assess Your Culture
It is essential for hiring managers, senior management, and the other decision-makers to clearly understand what the work culture actually IS - as opposed to what they HOPE it is. At a minimum, this process involves regular, thoughtful, open conversations with the people on your team/within your org. To ensure honesty, an anonymous survey may be needed first. Finally - having an external third-party observer “live” within your workplace for a time (a sort of “Undercover Boss”) and report back with their findings may be your best approach.
Fit? You’re Sure?
Next - before making a "fit" your highest priority, be sure a "fit" is what is needed. After all - "more of the same" drives homogeneity - and that can encourage "group think", limit innovation, and hamper organizational agility.
Trust Your People
Keep in mind that skills and knowledge are a lower priority when vetting candidates. Those can be taught. A willingness and ability to collaborate is harder to teach - so get the candidate in touch with your team (the people they would be elbow-to-elbow with daily), let them have far-ranging conversations, let them vet the candidate, and consider your team's assessment.
Whoa, whoa whoa! We just met!
More and more employers are finally wising up to the idea of recruiting for "Freelance to Permanent" positions. It’s a smart move. After all, why rush into "marriage" when you could first "date" for a while? If you think about it, job candidates (like first dates) aim to impress - arriving on time, well-dressed, all smiles, respectful, gracious. But if things start to turn south after three months - arriving late, unkempt, irritable, disinterested, self-occupied - why drag it out? So - when looking to fill a role, make it temporary and set a predefined date to regroup. On that date, the candidate (now freelancer), HR, and the hiring manager revisit the status of the “relationship” and decide if it’s time to get more serious (come on-staff full time) or start seeing other people (bring the employment to an end).
Sure - this might be hard for some hiring managers to embrace. "I don't want to risk it - if they come on for 3 months and leave, I'll have to train another one." Or "The money allocated for the role might go away next quarter - I don't want to lose that headcount". These concerns are real and understandable - but frankly, they pale in comparison to the peace-of-mind that comes with knowing "If the candidate is a bad fit or has a toxic personality, we're less than three months away from painlessly moving on and finding a new one. Who knows - the next one may even be marrying material".