Inside the 6 Stages of stack overflow's technical interview process

Programming blog

7 mins, 12 secs read time


Companies are eager to have a thorough process for conducting technical interviews, but it’s often difficult figuring out where to start. Sound familiar?

These bumps can be attributed to a lack of education for the interviewers and as a result, interviewers’ misalignment with the company’s hiring processes. (Yikes!). So, it’s important to decipher what’s currently working in your organization’s interview process...and what just needs work.

The good news is, there are many companies that have proven to be successful in this area (and we can learn from them!). One company in particular is Stack Overflow, a premier question-and-answer platform targeted at developers. As a mover-and-shaker in the tech industry, Stack Overflow has had a fair share of tech talent walk through its doors over the years. This means it has hundreds and hundreds of technical interviews under its belt—so it surely knows a thing or two about this topic!

In our latest Hiring Hacks webinar, Stack Overflow’s Engineering Manager Matt Sherman takes listeners through the company’s technical interview process. Even though it may be a challenge, conducting technical interviews the right way is important.

In this blog, you’ll learn how to create a stellar interview process to ensure you hire the right people, grow a solid team, and overall optimize your company’s technical efforts.

Recruiting: A Company-Wide Initiative

It helps when recruiting has been a company-wide initiative since day 1 (or as close to day 1 as possible!). Stack Overflow can attest to this, as it’s created a company culture from the get-go that is centered around recruiting, thanks to continual support from its leadership team.

Companies with executive buy-in have more engaged employees conducting interviews, which ultimately leads to better interview feedback for the hiring manager and recruiting team. Because leadership has encouraged a culture of conducting interviews well, interviewers are well-versed in this arena. They are confident in this role, knowing exactly which skills and qualities to look for in a candidate and how to read between the lines. And on top of this, they understand the important part they play in the hiring process—they know that their feedback and recommendation is instrumental in making a great hire and strengthening the organization as a whole.

This holds true at Stack Overflow—engineers on staff are an integral part of the technical interview process. Why? Having an actual engineer conduct the interview makes for stronger and more comprehensive interviews. These are the people who know whether a candidate would fit in culturally as well as whether they would be able to accomplish the volume of work necessary. And, they are the ones who would truly know whether a candidate can code at the level expected of them. And from a candidate's perspective, this set-up allows them to see firsthand who they would be working with and learning from.

In order to create this thoughtful experience, Stack Overflow provides observational interview training as well as mock interview training for each interviewer at the company. Thorough training is crucial to ensure that the interviewer feels prepared and comfortable in their role come the real interview. The icing on the cake is that they will rub off that comfort and relaxation onto the candidate, making for the best interview possible.

Stack Overflow’s Competitive Advantage

Beyond its three physical office locations, Stack Overflow staffs remote workers in over 10 countries! [If your company is not in the most desirable of locations (e.g. large metropolitan areas), ask yourself if staffing remote engineers is a possibility. If so, this would open up the gates, allowing you to reach more of the talent pool].

With the number of remote workers Stack Overflow hires, in-person interviews are actually a rare occurrence. Almost all interviews are conducted online through Google Hangouts. The online format means a bigger reach to more talent, but it also means that there must be a solid interview process in place in order to make the online format successful.

So, how do they do it? There are 6 stages to their technical interview process:

Stage 1

The first stage is the initial résumé review stage, simply known as TEDPG: target, experience, depth, passion, and “get things done.” Let’s define these terms:

  • Target: Make sure that the candidate has a targeted application for the job in question—that it’s not a generic résumé they are sending to other companies, too.
  • Experienced: Engineers must have 4-6 years of experience and be full stack engineers.
  • Depth: A candidate's résumé must show that they are not just familiar with the basics of certain softwares but that they know how to use them inside & out.
  • Passion: The résumé must reveal that the candidate absolutely loves programming—that, perhaps, it’s a focus inside and outside of the office.
  • Gets Things Done: The candidate should be able to complete a project from start to finish by a stated deadline.

Stage 2

If a candidate has four out of five of the above attributes, they are moved on to a 30-minute code screen. The code screen interview is an “easy” stage in the interview process. Matt shares that it simply allows Stack Overflow to see whether candidates can provide a solution quickly and efficiently, which speaks to their ability to “get things done” by a firm deadline. If they are not able to complete the screen in 30 minutes, they will not move on to the next stage, the smart interview.

Stage 3

The smart interview is an in-depth algorithmic question. This interview is supposed to be challenging, but at the same time, it’s meant to be conversational. At Stack Overflow, it is important to hear the candidate's thought process and understand how they’ve arrived at the resolution—it’s not just about the destination; the journey is significant, too. By asking them to walk through the process out loud, the hiring team can see if the candidate embodies the thinking skills and characteristics that are needed in the role.

Stage 4

If the candidate passes the smart interview stage, they then partake in the “get things done” interview. Here, the candidate designs an entire application. Since Stack Overflow only hires full stack engineers, it really wants to see how an engineer can develop an application from beginning to end.

Stage 5

So, the candidate has now gone through three technical interview stages, providing Stack Overflow with a clear indication of the candidate’s suitability for the role. Following the technical screenings, the candidate also meets with a member of the product management team so that the candidate can be familiarized with the goals of the business as a whole, not just with the goals of their own department. Stack Overflow sees meeting with the product team as a great opportunity to provide a comprehensive understanding of the company. Since ultimately the engineer will be building out certain products for users, it’s important for everyone to not only be aligned in the process but to also gain insight into what makes users happy.

Stage 6

Lastly, the VP of Engineering will read through each of the other interviewers’ feedback. This helps to prepare them for the last interview stage, where they will try to “sell” the candidate on the position. Selling the candidate shouldn’t just be about “Hey, we want you” but rather, describing in depth what the candidate would take on, should they accept the role, and how the opportunity would match and help to magnify their professional aspirations.

The Secret Is in the Conversation

What really sets Stack Overflow apart from other tech companies is that each interview it conducts is not meant to be intimidating and is not meant to be a quiz. Instead, all of Stack Overflow’s interviews are meant to be a conversation. As previously touched on, even when the candidate is presented with code tests, Stack Overflow likes to hear the candidate's thought process, especially if they made a mistake (since that happens in real life). That way, the company can see in detail how they approach a problem and, ultimately, how they solve it, even when inevitable obstacles get in the way.

Want to receive additional tips and recommendations on how to optimize your technical interview process? Listen to the full webinar here. Learn tactics to get in front of and engage engineering talent and see which reading materials you should grab ahold of to increase your engineering vocabulary.

How Stack Overflow Interview Engineers