Network Engineer Interview Questions: How to Prepare

During the job interview process, network engineers can expect a series of questions that range from the technical (such as the tools and techniques you’ve used to build and maintain networks) to the interpersonal (such as how you’ve used “soft skills” like communication and empathy to support your team).

Depending on the company and the interviewer, you might also face questions about troubleshooting performance issues, carrying out network monitoring, or configuring security systems such as firewalls. In other words, a network engineer interview often gets very detailed very quickly—you need to be prepared.

But how can you prepare? Let’s explore some possible responses to common network engineer interview questions, and how a few straightforward techniques—such as highlighting your positive impact on your previous employers—can help you stand out in a crowded marketplace.

Opening Questions Often Focus on Network Typology

According to DevSkiller CTO Tomasz Nurkiewicz, the first questions in any network engineer interview are likely to focus on the networks you’ve previously worked on. Examples include:

  • How were the networks separated from each other?
  • How did you organize the network and what kind of topology?
  • What were the security measures?
  • What were the monitoring and monitoring tools that you use?

The interviewer will also probe how you reacted to common incidents. For example, if employees had connectivity issues or were seeing some strange behavior in the network, how did you respond, and with what tools?

“I wouldn’t ask explicitly about a post-mortem, but more along the lines of: How did you make sure this doesn’t happen again? Did you did you come up with a procedure and did you document it?” Nurkiewicz added.

An interviewer might also ask about how you arranged coverage during your absences (such as vacation), which shows your capacity for planning. Given the current trends in the network engineering field, you’ll also be asked about your experiences with automation and scripting.

“The days where everything regarding the network infrastructure and network engineering was like fully manual are probably gone,” Nurkiewicz said. “There is a whole movement of having everything in code and setting up networks as like kind of more or less automated and declarative manner.”

Focus on Experience, Highlight Solutions

Nurkiewicz said it’s important to focus on actual experience, such as how you respond under stress or to an incident or security issue. “If there was recently some sort of vulnerability, it’s really great to mention that,” he said. “Perhaps there was some security vulnerability that was extremely influential, some backdoor vulnerability in a popular router.”

Some interviewers may open with a question about a well-known (or just-discovered) vulnerability, just to test the network engineer’s awareness of the industry’s current news. “This tells you whether a candidate has only theoretical knowledge or if they follow the trends and knows what’s going on in the wild,” he said.

When asked questions about your past work experiences, it’s important to explain how the decisions you made impacted the organization; for example, if you took the initiative and installed a piece of software that improved the network in some radical (and measurable) way. Or if you developed an innovative approach to filtering messages in order to prevent a malware issue. Such stories illustrate how you know the business needs and can react to those needs using your technical abilities.

“Focus on the way you impacted the company,” Nurkiewicz said. “If you can say you managed to decrease cloud costs by 10 percent because you installed software, that’s awesome. If you fixed a bug that was bothering your company for half a year and, and it was just a single line, but no one else found it—that’s perfect, because it shows you actually care.”

Prepare for Test Questions on Configuration, Cost Impact

When it comes to the testing portion of the interview, possible tests could vary depending on what the company wants from the candidate. For example, if the company is building out its cloud capabilities, and wants different clouds to talk to one another with a minimal set of privileges, prepare to be tested on that.  

Some practical interview questions could include:

  • How do you configure power or firewalls?
  • How do you configure private networks and VPNs?
  • How do you configure kind of bridges between clouds?
  • What’s the impact of that on costs?

With the aforementioned cloud example, a candidate might have to physically configure a network connection between two clouds or ask the candidate to install a certain firewall or antivirus software.

“As mentioned, they do need to understand what the company needs are and how they can help,” Nurkiewicz said. “Be prepared to prove you understand the choices may make a significant impact on how much the company pays for hardware or cloud costs. This is where the big impact can come from.”

2 Responses to “Network Engineer Interview Questions: How to Prepare”

  1. ITAngel

    Been a NW Engr for ~38 yrs. Experienced 80s, 90s, 00s, 10s, and now. The interviews have always been crazy technical. Most other NW Engrs interviewing you will be sadists that get kicks out of tripping you up and embarrassing you. You could answer 99/100 questions right and they will focus only on the 1 question you got wrong. I have been NW Engr, NW Admin, NW Designer, NW Architect, Project Mgr, Project Lead, Tech Lead, Team Lead, IT/NW Mgr, Dir Of IT, and Sr/Principal Consultant. Over 38 years, I’ve learned one thing: all NWing guys are @/$/$/h/0/L/3/$. They are super smart people that think intelligence gives them a license to be complete @/$/$/h/0/L/3/$. As a IT Mgr and IT Dir, I have learned that if I don’t corral in my NW Engrs, they will run amuck like a bunch of wild stallions broken out of a corral. NW guys are smart, yes, but they know it. Alongside everything else they use to do their jobs, one of their most-used tool is their arrogance. Never forget that. NWing interviews are, in the end, all technical. I study on average for ~3 days straight before each NWing intyerview I attend as an employment Candidate. And most of the time, I still end up not getting asked much at all about anything I know or have studied. Again, NWing guys are @/$/$/h/0/L/3/$ that love to embarrass other NWing guys. I’m 61 now, but if I could do it all over again, I would never have gotten into this NWing and IT world. I would’ve become an Emergency Room Surgeon and a Professional Touring Musician like I’ve always wanted to be. Compared to coming up in this industry in the 80s, 90s, 00s, etc, IT and the people in it sucks the complete bag these days.

    • ITAngel

      EDIT:
      Been an NW Engr for ~38 yrs.
      Experienced 80s, 90s, 00s, 10s, and now.
      The interviews have always been crazy technical.
      Most other NW Engrs interviewing you will be sadists who get kicks out of tripping you up and embarrassing you.
      You could answer 99/100 questions right and they will focus only on the 1 question you got wrong.
      I have been NW Engr, NW Admin, NW Designer, NW Architect, Project Mgr, Project Lead, Tech Lead, Team Lead, IT/NW Mgr, Dir Of IT, and Sr/Principal Consultant.
      Over ~38 years, I’ve learned one thing: all NWing guys are @/$/$/h/0/L/3/$.
      They are super smart people whom think intelligence gives them a license to be complete @/$/$/h/0/L/3/$.
      As an IT Mgr and IT Dir, I have learned that if I don’t corral in my NW Engrs, they will run amuck like a bunch of wild stallions broken out of a corral.
      NW guys are smart, yes, but they know it.
      Alongside everything else they use to do their jobs, one of their most-used tools is their arrogance.
      Never forget that.
      NWing interviews, and hiring decisions, are, in the end, ALL technical-based.
      I study on average for ~3 days straight before each NWing interview I attend as an employment Candidate.
      Most of the time, I still end up not getting asked much at all about anything I know or have studied.
      Again, NWing guys are @/$/$/h/0/L/3/$ who love to embarrass other NWing guys.
      I’m 61 now, but if I could do it all over again, I would never have gotten into this NWing and IT world.
      I would’ve become an Emergency Room Surgeon and a Professional Touring Musician like I’ve always wanted to be.
      Compared to coming up in this industry in the 80s, 90s, 00s, etc, IT, and the people in it, sucks/suck the complete bag these days.