You’ve done all your prep, and now the candidate is sitting there looking at you. You have an hour, at the end of which you are supposed to have a smart and insightful analysis on whether to hire them or not. How do you spend your time?
Have Them DO Something – Don’t Ask General Questions
One of the most common mistakes is to ask open-ended softball questions. “What are your strengths and weaknesses?” The candidate then babbles on about how disciplined and passionate they are, and how their big weakness in life is that they just work so hard, and take things so seriously – they struggle under the burden of an extreme work ethic that was just the despair of their former managers. And now several precious minutes of your interview are gone, and you haven’t learned a darned thing.
I think it’s infinitely better to ask them to create something. Write code on the board for a multi-threaded lock implementation. Write the Javascript code to update the notification count when a new message arrives. Design a UI for managing notifications. Design a set of metrics to monitor the state of the business. Create a plan to track and land a milestone. Whatever is appropriate for the job you need them to do.
If the design involves a skill they need to have, you will quickly see whether they really have it. Many people can do a lovely job describing a design they know but are lousy at creating one. Confronting a blank white board and having to invent something on the spot cuts through a lot of blather. If it’s a skill they are still learning, you will also discover a lot in watching them try to tackle a real problem.
What To Look For
When I pose a design problem, whether the result is an algorithm or a visual design or a report or anything else, beyond the quality of the work, I’m assessing a number of other things:
- Do they like solving this kind of problem? Of course there is some added stress because it is an interview, but you can usually tell if they are enjoying the opportunity to dig into the problem or not. I try hard to make an interview feel as much as I can like the real job – sometimes I will pose a problem that I’m actually trying to figure out at the time. If they hate doing it in the interview, they probably aren’t going to love doing it all day long.
- Do we make each other smart? If we’re going to be working together in the future, hopefully we have a good working rapport. Did the design conversation zip along efficiently and cover ground well, or were there constant misunderstandings and false starts?
- Do they handle pushback well? I always question some of their decisions (politely, of course). How they handle that will tell you a lot. The worst reaction is if they get mad, or they dogmatically insist that theirs is the best approach without explaining why. Almost as bad is if they cave immediately and ask what you think they should do instead. A great reaction is to explain the rationale for the original design, and to list a couple of alternative approaches and why they seemed less effective. I hope they welcome new data, if I share something useful that would influence the design in a better direction. In general, I want to know if they are passionate about finding the best answer, or about moving forward with their answer.
- How do they handle underspecified problems? I like to ask design questions without providing enough information, to see what happens. The two most common failure modes are to flail around and to make wild sweeping assumptions. If I ask you to design an airport, do you just freeze up, do you assume that it is LAX (rather than, say, an oilfield airport in Alaska), or do you ask? In general, I’ve found that people who fall into either of those traps often have trouble if they get hired. The freezers aren’t good at taking on hard new problems without having their hand held, and the assumers bull off in wrong directions and get themselves (and their teams) into a mess.
Other Questions I Like
Once you have figured out whether they can do the work that is most important for your role, there are other questions that I’ve found effective:
- Teach me about X. Pick something that looks interesting in their resume – a skill they say they have, a project they worked on. Have them teach it to you. If it involves a design they did, ask them why they made certain decisions, and what they would have done differently in retrospect. At the end of the discussion, do you feel well informed about the topic? Any job I hire somebody to do will almost certainly involve explanations of complex topics, so it’s an important skill in its own right. And, it will help you figure out how well they actually understood what they were working on. If a very attentive listener can’t get a decent grasp of it quickly, they probably didn’t.
- How would YOU interview somebody for this job? This is a fun question, and I’ve found it is really useful. It helps me understand what they think is important about the role and how thoughtful they are about testing for those characteristics. It also reveals whether they have insight into other people and how to work with/manage them.
- Share a great success and a disappointing failure in managing other people. What did you do, how did it come out, and what did you learn? If the person is interviewing for a management role, I want to know how they think about other people. Are they insightful? Do they passionately identify with the success of the people whom they managed? If you are an experienced manager, you are pretty much guaranteed to have succeeded with somebody and failed with somebody, so you should have some interesting stories to talk about. I also often pose a scenario – “Margaret is a superstar but runs roughshod over others, and you are going to give her a tough review calling her on it. How do you prepare, what do you say, how do you handle it when she attacks you …”
Making the Call
At the end of the interview, you have to make a decision – “hire” or “no hire”. Often, it’s obvious. But if there is any doubt in my mind, I find it really useful to write down the reasons and talk them through with somebody else who has made a lot of hiring decisions. By the time I finish explaining the analysis, I almost always realize that I’ve made up my mind, and can ground the answer in solid reasons.
The people you hire will largely determine how successful your team is, so choose wisely. Good luck!