Jacob Kaplan-Moss

Checking References:

Yes, You Should Check References

There’s a bit of a meme out there that checking references is outdated. I get where this is coming from: a good interview process can build a ton of confidence in the person you’ve selected, and there’s a degree to which checking references can feel pro forma. But I disagree: reference checking isn’t optional; it can save you from making a big mistake.

This is the first in a short series on checking references. I’ll cover:

  1. Why you should check references and the difference between formal and informal reference checks (that’s this piece)
  2. How (and when) to check references
  3. What to do if a reference check turns up something unexpected

Why are reference checks important?

To get us started: why do I say that reference checks are important?

Put simply, reference checks are your last line of defense against hiring jerks. Work sample tests will measure required job skills, but can fail to screen out people who will fail the “works well with others” requirement. Good interview questions can often detect jerks, but can miss a certain class of smooth-talkers – people who can bluff their way a question about conflict resolution but in reality behaves like a jerk. Reference checks are how you catch this kind of smooth-talking, competent jerk. These people are rare, but they do exist, and without a reference check you’ll almost certainly discover too late.

Reference checks can sometimes turn up less extreme information. A friend told me a story about hiring someone for a public-facing role (something like a developer advocate role) who turned out to be very uncomfortable with the level of public visibility required. That’s hard to measure in an interview but might have come up in a reference check. (Whether that would have been a dealbreaker is another question, which I’ll talk more about in the third part of this series.)

Finally, in the best case, reference checks can turn up some additional context that can help you become a better manager for this person more quickly. Once on a reference check call, I had a person’s former manager tell me that they get incredibly nervous if they’re not getting frequent, almost daily, feedback. My style is usually to hold off giving feedback to a new member of my team for the first 6 weeks or so, until we’ve built a bit of a relationship. But in this case, that might have started off our relationship on the wrong foot. I’m grateful to that previous manager for the tip!

The one exception to requiring references: entry-level candidates

I do have one exception to my rule that you should always conduct a reference check, and that’s for the most junior, entry-level candidates. If you’re hiring someone into what’ll be their first job – someone straight out of (or still in) school, someone entering the workforce for the first time – they’re unlikely to have useful references. I don’t see much point in talking to someone’s teachers/professors; the kinds of jobs I hire for are so unlike school as to make someone’s behavior in class nearly irrelevant. Nor do I see the point in making someone with no work experience come up with some family friend or neighbor for me to talk to; again, irrelevant.

So, for positions where I’m considering candidates without any work experience – true entry-level jobs, internships, etc. – I’m comfortable skipping a reference check.

Formal versus backchannel reference checks

There are two ways you might conduct a reference check:

  1. Ask the person for a few references, and contact them. This is the “standard” way reference checks are conducted; I’m calling it a “formal” reference check.
  2. Find a mutual connection — e.g. “oh, my candidate worked with Jane Smith, who I know from the Python community” — and reach out to them about the candidate. I call this a “backchannel” reference checks

Backchannel reference checks can be valuable, but they need to be conducted with a great degree of care. Letting someone’s colleague or boss know that they’re job hunting is super fucked-up, so you can’t just spray off emails to people you don’t know. You need to find someone that knows the candidate well enough to give you accurate information, and that you know well enough to trust that they won’t use the knowledge that the person is looking against them.

That’s difficult to pull off, so you can’t require backchannel reference checks. It’s unfair to reject a candidate because you can’t find a backchannel reference – if you do, you’ll only hire out of your echo chamber.

I do use backchannel reference checks, but very carefully, and typically much earlier in the hiring process. I use them essentially as a screen and a gut-check: if we have a trusted mutual connection I’ll ask for impressions. If I get an “oh HELL YES” I might move them to the front of my interview queue; if I hear that they’re terrible to work with I might use that information to dig much more deeply during interviews. Otherwise, I don’t put a ton of weight on backchannel checks; they’re just too prone to being unfair.

So in the rest of this series, I’ll be talking about formal reference checks. The next piece in this series will cover more details about what I mean by a formal reference check – when to do them, how many references, etc. Stay tuned!