This is my reference call cheatsheet when I am a reference, not as an interviewer.

Keep reading past the questions if you want some tips or things to look out for.

Preparing

Interviewing is hard and stressful, being a reference is essentially interviewing on behalf of somebody else: it's even harder.

Reference calls are a form of due diligence. So far the company is happy enough with the candidate, they're just making sure they haven't overlooked something terrible during the interviews.

Less talking is better than too much talking and risking a misunderstanding that could hurt your former colleague's prospects, it's the same philosophy as an interview with the USCIS if you were lucky enough to go through the experience.

Keep in mind who is calling you: they may be from HR, a manager, director, or even their future direct manager.

I'm not a professional reference call person, so I will only describe what I do and how I approach the process.

You're going to spend about an hour to help your former coworker, so feel free to ask them for a little help. When they ask you to be a reference, make sure to thank them, and then ask:

• what the role is
• what the company is
• [if needed] refresh your memory on a couple projects you worked on together

This will help find the angle you should be using when answering questions: if you worked together as an IC, and your former coworker is interviewing for a management position, you will want to emphasize both on technical ability, as well as leadership qualities, reliability, trustworthiness, etc.

I don't make stuff up, but I'm also trying to help my friend get a good offer.

"How long did you work together and in what capacity"

This is the one question you're guaranteed to have to answer. That's a freebie. So you might as well prepare for it.

Variations you can expect:

• How do you know candidate?
• In what capacity did you work with candidate?
• How long did you work with candidate?
• Can you describe candidate's responsibilities while working with you?
• What were their title and your title when working together?

Strengths and weaknesses

This is your second freebie.

While many interviewers try to avoid the question directly or find more modern ways of asking, in my experience for reference calls they will ask this question. Just like if you were interviewing for yourself, you want to present actual weaknesses or areas when they could grow, but nothing bad. Avoid anything behavioral or that is typically seen as something you cannot fix or coach. Possible answers:

• They don't promote their work enough
• They don't delegate enough
• They focus too much on the work and not enough on selling it

You want things that are easy for a manager to help with, and that are appropriate for the role/seniority.

"They don't delegate enough" may be ok for a senior engineer, but probably not for a director level position.

Variations:

• How can I be the best possible manager for candidate?
• What do you think candidate has grown the most on?
• What areas if developed further, would have the biggest impact on candidate’s effectiveness?

The Danger Zone™

This is the stuff you don't want to rush when answering:

• How would you rank candidate relatively to the engineers you’ve worked with in your career? What percentile?

You have to say they're top 25% or above essentially. If you can't say or are not prepared to lie about this, you should have declined to be a reference. Even 25% isn't great, ideally they're something like "top 10 engineers you've worked with".

• If we hire candidate and in 6 months it doesn't work out, what would you think would be the most likely reason?

Make sure to assume it didn't work out because the candidate was unhappy with the role: "not enough responsibilities", "no challenge", etc. Even if the question is worded in such a way that they imply that the candidate would be underperforming for a reason, turn it into they're underperforming because the new employer isn't a good fit.

• What do you think is the biggest contribution candidate has made to old company?

This is one of the questions where it would be bad not to have an answer.