Hiring a Data Scientist: What to Ask?


Hiring a data scientist is hard. There is no playbook and the options are many.  And to make things more complicated, Business Insider calls it the “best job in America right now“!

In the previous posts in this series we talked about the basics of the interview process.  But let’s dig into what happens when the Data Scientist shows up at your door for an in-house interview.

You’ve already figured out the who and when of the interview, but now you have to decided on the what:

  • What skills do you want the Data Scientist to have?
  • What do you want to know about the Data Scientist?
  • What questions can you ask to answer the above questions?

If you’re hiring a data scientist, hopefully you have some idea of what skills you want the Data Scientist to have before starting the interview process.  If not, you should take a step back and ask yourself why you are bringing this person in. Do you already have a data science team, or is this your first hire?  You may want to review “Types of Data Scientists” and “Hiring Your First Data Scientist“.

Understanding what the Data Scientist will bring to the team in a one hour interview is a much harder problem. We break down the line of questioning into five parts:

  • How did the candidate contribute to previous projects.
  • What tools and skills does the candidate use the most and how do they use them to achieve their goals.
  • How does the candidate think about new and/or unfamiliar data.
  • How does the candidate respond to being challenged and/or stressed.
  • How will the candidate fit in the current team dynamic.

A candidate must pass all parts and exceed in at least two or three to be considered being hired.  Each of the five parts are integral to the hiring process.  Here are some things to consider:

    1. Has the candidate been a team manager for many years with little recent hands on experience? If so, how will they do as an individual contributor?
    2. What are the goto tools, e.g. how do they attack a problem?
    3. How do they handle new situations and integration of data into analysis or systems?
    4. How do they react when their ideas or techniques are challenged in an adversarial way?
    5. Are they a team player?

Team dynamics is one the most important pieces of a company.  A candidate must get along with the interviewers, otherwise they could likely cause strife within the company. (This is most important in a small startup environment where everybody interacts with everybody else.)

Hiring a data scientist involves defining a set of questions that will help vet the candidate.  In the world of big data, these are questions the candidate should answer readily. They fall into these general categories:

  • Programming and algorithms
  • Data Modeling
  • Statistics and Methodology (e.g. frequentest vs Bayesian approaches)
  • System architecture, data flows, and technology
  • Interpersonal skills

Of course, the questions come from not only the level and experience of the candidate, but the flow of the interview and what seems appropriate at the time. Careful planning before the interview is the key to determining the best candidate for your company.

DesignMind’s Data Science team specializes in data mining, data modeling, and artificial intelligence.