Showing posts with label hiring. Show all posts
Showing posts with label hiring. Show all posts

Monday, May 3, 2021

How to hire well

How I've learned to hire

I’ve done a lot of hiring and I’ve learned what works and what doesn’t work to make a good hire (someone who performs well and stays). I’ve come to trust my judgment but only within the confines of a hiring process that covers my blind spots. Here’s a description of what I typically like to do, but bear in mind this is an amalgamation of processes from different employers.

To be clear: what I say in this blog post might not reflect current or previous hiring processes at my current or former employers. I'm presenting a mix of processes with the goal of giving you insight into one amalgamated hiring process and how one hiring manager thinks.

Principles - caution, excitement, 'no', and decency

The hiring process is fraught for both parties. We're both trying to decide if we want to spend extended amounts of time with each other. The hiring manager wants someone who will fit in, perform well, and will stay. The applicant wants to work in an environment that suits them and rewards them appropriately. No one enjoys the interviewing process and everyone wants to get what they want quickly. This suggests the first principle: caution. It's easy to make a mistake when the pressure is on and the thing that will save you is having a good process.

Once the process starts, I try and follow an ‘excite and select’ approach. I want to excite candidates by meeting the team and by the whole interview process and I want them to feel energized by what they experience. I then select from enthusiastic and excited candidates.

My default position is always ‘no’ at all stages. If I’m in doubt, I sleep on it and say ‘no’ the next day. On occasions, I’ve been under a great deal of pressure to make a hire, but this attitude has saved me from hiring the wrong person. Even in the US, unwinding a bad hiring decision is extremely painful, and in Europe, it can be almost impossible. It’s far better to be sure than take a risk. I’ve only changed my mind after a ‘no’ once, and that turned out to be a good decision that I stand by.

My next principle is being humane. The interview process is stressful and I want to treat candidates well and with respect at every stage. Even if they’ve been rejected, I want them to feel good about the process. Let's be honest, sometimes there's just a mismatch of skills - I've said no to some really great people.

(Interviews should be friendly and humane, not an interrogation or a stress test. Image credit: Noh Mun Duek, license: Creative Commons, source: Wikimedia Commons.)

The hiring process

The job ad

I like to think very carefully about the wording of the job ad. It has to excite and attract candidates, but it also has to be honest and clear about the job.

I've had a few candidates who've misunderstood the job and that's become clear at the screening interview. To stop this from happening, I've sometimes created a longer form job description I've sent to candidates we've selected for screening. The longer form description describes more about the role and provides some background about the company. Some candidates have withdrawn from the process after seeing the longer form description and that's OK - better for everyone to stop the process sooner if there's no match.

Resume selection

This is an art. Here are some of the factors I consider for technical positions.

  • A Github page is real plus. I check out the content.
  • Blog posts (personal or company) or content for marketing is a plus.
  • Mention of methods and languages. Huge shopping lists of languages are a bad sign. I also want to know what they've done with languages and methods.
  • Clear descriptions of what they've done, with a focus on the technical piece. I prefer straightforward language.
  • Training courses. Huge shopping lists are again a no for me.

I don't tend to select on the college someone went to but I know lots of organizations that do.

The screening interview

The first interview is a screening interview with me as the hiring manager. I do this via video call so I can get a sense of the person’s responses and their ability to interact. I always have a script for these calls and always follow the same process. I work out the areas I want to talk about and create the best questions I can to differentiate between candidates. The script gives me a more consistent (and fairer) way to compare candidates and also enables me to learn what works and what doesn’t. For example, if candidates find a question confusing, or everyone answers a question well, I can change the question. For behavioral questions, I ask for examples of the behavior and my technical questions are usually about experience. Here are some examples:

  • Can you give me an example of how you dealt with conflicting demands?
  • Can you tell me about a time you managed an underperforming employee?
  • What’s the largest program you’ve written?
  • What are the biggest limitations of Python?

These questions are launch points for deeper discussions.

The technical screen

Next comes a technical screening. Again, this must be the same for all candidates. It must be fair and allow for nervousness. 

I'm very careful about the technical questions that my interview team asks. I make sure that people are asked relevant questions that reveal the extent of their knowledge and skills. For example, if my team were interviewing someone for a machine learning position, I would ask about their use of key libraries (e.g. caret), but I wouldn't ask them about building SVMs or random forest models from scratch unless that's something they'd be doing.

Cultural fit and add

Finally, there are in-person interviews. I like to use teams of two where I can so two people can get a read. Any more than two and it starts to feel like an interrogation. Each team has a brief for the areas they want to probe and a list of questions they want to ask. 

Team selection is something of an art; I’ve known interviewers who are unable to say ‘no’ to any candidate, no matter how bad. If I have to include someone like this on the interview team, I’ll balance them with someone who can say no.  

I’ve heard of companies doing all-day interviews, but this seems like overkill to me and it stresses the interviewee; there’s a balance here between thoroughness and being human. For in-person interviews, I ensure that every team offers the candidate a drink or time out to visit the restroom. 

Where I can, I have the very last interview as a discussion with the candidate, asking them what went well and what went badly in the process. Sometimes candidates answer a question badly and use the discussion opportunity to better answer the question. Everyone makes mistakes and interviews are stressful, it seems like a good opportunity to offer the candidate a pause for reflection and an opportunity to correct errors.

I always look for the ability to work well with others and I value that over technical skills. A good technical person can always learn new technical skills, but it's very difficult to train someone not to be a jerk.

Decision making

Before we go to a decision, I find people the candidate may have interacted with who are not on the interview team. Many times, I’ve asked the receptionist how the candidate treated them. On one occasion, a candidate upset the receptionist so badly, they came to me and told me what had happened. It was an instant ‘no’ from that point.

To decide hire or no hire, I gather the interview teams together and we have a discussion about the candidate. If consensus exists to hire, most of the time I go ahead and make an offer but only after probing to make sure this is a considered opinion of everyone in the room. On a few occasions, I’ve overruled the group and said no. This happens when I think some factor is very important but the group hasn’t considered it well enough. If the decision is a uniform no, I don’t hire. I reserve the right to overrule the group, but it’s almost inconceivable I’d overrule a uniform no. If the view of the group is mixed, I probe those in favor and those against. In almost all cases where views are mixed, I say no - this is part of my default ‘no’ position.

The benefits

I know this process sounds regimented, but there are important benefits. The first is fairness for candidates; everyone is treated the same and there’s a consistent set of filters. The second is learning; if the process is wrong or has failed in some respect, we can fix it. Thirdly, the process is inclusive - the team has a huge say in who gets hired and who doesn’t.

If hiring and retaining good staff is important, then it’s important to have a fair, decent, and thorough hiring process. Through years of experience, I’ve honed my process and I’ve been pleased that the companies I’ve worked for have all had similar underlying processes and similar principles.

Good luck

If you"re searching for a job, I hope this post has given you some insight into a hiring process and what you have to do to succeed. Good luck to you.

Saturday, January 18, 2020

How to be a good candidate for analytics and data science jobs

Over the last few years, I’ve done a lot of hiring across many disciplines: analytics, data science, product management, engineering, sales, and HR. I’ve learned a lot about what makes a good candidate and what makes a bad candidate. Because I’m writing this blog for people interested in analytics and data science, I'm going to share some of the things that I think are likely to improve your chances of getting hired for technical positions.

(Image credit: Grey Geezer at Wikimedia Commons - license. Image unchanged.)

Hiring is risky

The key thing to remember is hiring is a tremendously risky process for the employer. It’s very painful to unwind a poor hiring decision, so for the most part, the interview team is not inclined to take risks. You have to satisfy the technical requirements for the job, but also the social requirements too. The interview team will be deciding whether or not you’re a fit for the team - can they work with you? There are all kinds of clues they use to decide this and I’ll cover some of them here.

Resume blunders

Candidates make amazing blunders with resumes. I’ve seen odd layouts, poor wording, and incredibly long resumes (15+ pages in one case). Here are some simple rules:

  • Length: one page if you’re junior, two pages (at most) if you’re senior.
  • Layout: single-column layouts - keep it simple.
  • Keywords: your resume should use every relevant keyword as many times as it makes sense. For example, if you have machine learning experience, use the term. Resumes are often keyword screened and if you don’t have the keywords you’ll be ruled out by an algorithm.
  • Contact details: name, city, phone number, email. I always give local candidates preference, but I have to know you’re local.

Your resume gives clues to how well-prepared you are (back to the risk thing), a bad resume indicates you haven’t taken advice, or you don’t care, or you’re naive, none of which are good. There are plenty of good resources out there for building resumes. Northeastern University does an incredible job preparing its candidates for work, including some great coaching on resume building. They have an excellent website on resumes with lots of strong guidance.

One great piece of advice I’ve heard is to customize your resume for the employer or industry you’re targeting. Some candidates are considering different employment areas but they have a single resume they’re trying to use for everything. You should have a different resume focusing on different areas for each industry you're targeting. If you have time, you should tweak your resume for each employer. Remember that customization is as much about what you leave out as what you leave in. For example, if you have wet bench experience but you’re applying for computing positions, you should shorten (or remove) your wet bench sections and increase the length of your software sections. The logic here is simple, you have limited space, so why tell an employer about something irrelevant to them? For me, there’s a minor exception - I do like candidates with something unusual about them, but a single resume line is usually enough (e.g. ‘wet bench qualifications’, ‘EMT qualified’).


I love it when candidates have a Github page they put on their resume. If they pass the screening interview, I check out their page and what they’ve done. You do need to be careful though, I’ve seen some bad code that’s put me off a candidate. Github is especially great if you’re trying to do some kind of career transition into analytics or data science from some other field. If you’re transitioning, you can’t talk about what you’ve done in your current role as proof of your capabilities, but you can talk about the Github projects you’ve created in your own time. In fact, creating a project in your own time to display your work shows a tremendous amount of commitment. If you have projects to put up on Github, do so, it’s a great place to demonstrate your talent.

Be prepared - and turn your camera on

If you haven’t interviewed in a while, it’s a good idea to reach out to your connections and ask for a practice interview. You could also ask your friends for a review of your resume. Of course, you should remember that if people help you, in turn, you should help people.

For heaven’s sake, be technically prepared for the interview. Nowadays, many interviews are conducted via a computer video call (e.g. Skype, Zoom, etc.). There’s almost always software to download and install. Make sure you have the software installed and running before the call.  I interviewed someone for a management position who took 20 minutes to download the software and get into the interview. Not good when you’re interviewing for a position that requires experience and forward planning!

For video interviews, I have two pieces of advice: turn your camera on and consider where you do the interview. It’s a video interview for a reason and it looks odd if you don’t turn your camera on. I was once told that the reason why a candidate didn’t turn their camera on was that they’d had an unusual hair treatment just before the call. Your hair is your business, but why not schedule the call for some other time? You also need to consider your background; what will the interviewer see? I was once interviewed by someone from a hotel bedroom with their underwear strewn everywhere in the frame - it didn’t create a professional impression. One candidate I interviewed had their laptop on their knees for the interview; every time they moved the entire video frame heaved like a ship in a storm and by the end of the interview I felt seasick. Try to avoid distracting locations and distracting items in the frame.

Preparation also means understanding who will interview you and what the interview will cover. I’ve interviewed candidates who were surprised to be asked technical questions when the interview briefing clearly said that would happen. 

Of course, you must look up everyone on LinkedIn beforehand and know their roles - you might even get insight into the questions they might ask.

Examples and questions

A few years ago I did a course on behavior-based interviewing. There were lots of great pieces in the course but it can be boiled down to one simple idea: give examples for everything you claim. For example, if you claim to be a good planner, give examples of how you planned well, if you claim to know Python, point to examples (e.g. Github), and so on. The idea is you’re providing proof - doing is better than saying.

Make sure you have plenty of questions for each interviewer. It shows you’re prepared and engaged, and of course, you might learn something useful. It’s also expected. If you can, get every interviewer’s email address, you’ll need it later.

At the end

When it’s all over, send a thank you email to everyone who interviewed you. For any kind of customer-facing role, this is expected and it’s increasingly expected for technical roles too.

If you don’t get the job, there’s one last thing you can do. If you got on well with the interview team, ask for feedback. Not every interview team will do it, but some will and you can learn a lot from them about why you didn’t get the job.

Final thoughts

Bear in mind that a lot of what I’ve said is about reducing risk for the employer in choosing you. Being prepared for the interview (software download, video call background, interview questions, etc.) shows you take it all seriously and gives clues to what you’ll be like as an employee. Asking questions at the interview and thanking everyone shows you know about social conventions and could be a good fit for the team.

Good luck!