How to prepare for a sysadmin interview
So you scored an interview for a system administrator role. The job’s as good as yours, right? It’s almost surprising that they haven’t gone ahead and granted you root privileges.
Let’s not get carried away. It’s good to believe in yourself, but treating a job interview as a formality isn’t confidence. It’s hubris, which you won’t find on many lists of "interview best practices." Any good team or organization—as in, the kind most of us want to work with—is definitely not treating your interview as an afterthought. This meeting is their chance to get to know you as a person, to dig into your skills and experience, and to fully evaluate you as a candidate for their open sysadmin position.
In other words: It’s not time to celebrate just yet. It’s time to prep. We’re here to help you put your best foot forward, with tips from a range of experts who’ve been on both sides of the hiring table. In particular, we asked these IT pros and hiring managers to share pointers specifically for sysadmin interviews—the nature of which, like the role itself, may have changed since the last time you were on the market.
Whether you’re a veteran sysadmin, new to the field, or somewhere in between, consider this article as a checklist of sorts as you prepare for your next interview.
Study the job description (Seriously)
You might be thinking: I already did that. Maybe you did. But every seasoned recruiter and hiring manager has a story or three about interviews where the candidate appeared to have skipped this step.
"Carefully read the job description to understand what is expected from this role," says Ceren Güvenç, HR director at AnyDesk.
Doing so is especially crucial for sysadmin positions. This job title has been an IT staple for years, but it means different things in different organizations, just as other common job titles (think: "software engineer") can represent very different roles and responsibilities in different companies.
The job description is your starting point for understanding what *this* company needs. In particular, it should (hopefully) give you a better idea of the technology stack (or stacks, in some cases) you’ll be responsible for, what kind of environments the company operates, what tools you’ll be working with, and so forth. So, again, read the job description closely. It’s the foundation for a successful interview.
Refresh on the fundamentals
The sysadmin role (like many others in IT) keeps evolving in the modern era, but many of the fundamentals remain, well, fundamental. Make sure you're at ease discussing the key technical principles of system administration. You interviewer will take note.
"Know your technical fundamentals," advises Sam Larson, director of service engineering at OneNeck IT Solutions. "Be able to describe in plain language how all the parts of a server (hardware) and operating system (software) work together. Be able to do the same for the OSI model, LAMP, RAID, DNS, and basic virtualization concepts."
Better still, invest the time to make sure you can discuss key technologies and concepts in a real-world manner. Even if you’re a junior sysadmin, you can get your hands dirty and build some practical experience through experimentation.
"Be prepared to discuss interesting examples of both configuring (setup) and fixing (incident response) all of those technologies," Larson says. "If you don’t have interesting examples, create some. Read about those technologies, set them up in the lab, break them, and then fix them."
Do your homework on modern tools and technologies
Again, the job description hopefully included some level of detail on the company’s technology stack and toolsets. But don’t stop there: Make sure you can talk knowledgeably about the major technologies used in modern IT.
Exhibit A: Automation. All of our IT pros and hiring managers emphasized its importance for today’s sysadmin.
"Besides the basic knowledge specific to the systems you are going to manage, it's really important to be familiar with automation technologies that are being widely applied to IT management," says Marcio Saito, CTO at Opengear.
Larson from OneNeck IT Solutions breaks down automation into key subsets that you might be asked about: automated configuration management tools, containerization, container orchestration, source code management, and continuous integration/continuous deployment.
Exhibits C and D: "Cloud and DevOps are the top technology skill sets being recruited for [today]," says Julie Gunderson, DevOps advocate at PagerDuty. (Gunderson also has experience in a technology recruiting role prior to her current position.)
If you don’t have experience with any of the major cloud platforms, Gunderson suggests pursuing a certification to jump-start your learning curve.
"Understand how the cloud is architected, how to support server migrations to the cloud, and how hybrid cloud environments function," she says.
Prepare to discuss evolutionary trends
In all likelihood, you’ll be asked how these technologies and trends are changing traditional IT models and roles, including the sysadmin position.
"Managing any type of IT system – be it server, storage, networking – has changed (or is very much in the process of changing) from a traditional Operations model into a DevOps model," Saito says.
Even if the company doesn’t actively call itself a DevOps shop, it’s probably incorporating the principles of DevOps culture (such as breaking down traditional silos) or the tools and technologies (like those mentioned above) commonly associated with DevOps. Larson recommends being prepared to talk about DevOps and also possibly Site Reliability Engineering (SRE).
"These new practices take lessons learned from agile software development and apply them to systems administration," Larson says. "At their core lies the idea of using code [and] automation as much as possible. This is something good sysadmins have always done. New tools and practices have just increased the number of tasks it is possible to automate, and made that automation easier."
Be ready to offer details on your skills and previous work
If a topic is on your resume or online profiles, you should be ready to speak about it with substance. (If not, it’s probably best to remove that topic.) Güvenç from AnyDesk notes that confirming and expanding upon the information on your CV is a common starting point for interview questions.
Güvenç also shares three other questions you should be ready for, based on your resume:
- List which technologies you have experience working with.
- Share projects (or other examples) that elaborate on your skills and experience.
- Describe the most difficult problems you had to troubleshoot in past positions.
Practice answering (more) interview questions
Güvenç’s examples are a great starting point. Odds are that you'll be asked more than a handful of questions, so spend time preparing and practicing for other possibilities. You probably won't know the questions in advance, though, so don’t stress out. Just practice for various possibilities so that you’re comfortable answering in the moment—the goal isn’t to sound like you’re reading from a script.
Here are some other topics our experts recommend gearing up for.
The staples of sysadmin interviews
"Basic troubleshooting questions around end-user issues should be expected, such as adding and removing new software, configuring permissions and network protocols," Gunderson says. "Specific questions around Active Directory configuration, load balancing, run levels, and virtualization are a staple in system administrator interviews. Also, be ready to discuss what programming languages you have experience with and how you used them in your past experience."
How a particular technology or system served a business goal
"Technical competency and the ability and initiative to leverage automation are table stakes. I also look for an ability to connect the dots between a technology and the business application it’s serving," Larson says. "The systems you’ve worked on in the past don’t have intrinsic value but they do have intrinsic costs. It is important to understand how they generate value."
The pros and cons of [insert tool or technology here]
"I look for clarity of thought. For example, if I ask you what the pros and cons of a technology are and you reply by describing what the technology is, I would view that as an incorrect answer even if the description is accurate," Larson says. "That is an important example. Knowing the pros and cons of a tool or technology can be more valuable than knowing how it works. The pros and cons tell you when or if you need to use it. ‘How’ is only important after you’ve accurately identified a need."
Details about specific environments
Depending on the environment, be prepared to answer specific questions around different operating systems, networks, databases, security and configuration management," Gunderson says. "You will also be asked questions about the size of your previous environments and teams."
This last topic gets us back to the beginning: read the job description carefully. Güvenç also notes that the company and its environment size will play a key role in what the employer is looking for. A Sysadmin in a small company is more likely to play a jack-of-all-trades role, whereas in a midsize or larger company with deeper pockets, the Sysadmin might be more specialized or focused on a particular environment or technology stack.
Your commitment to ongoing learning.
"When interviewing candidates, I tend to lean more towards the candidates desire to continuously learn and grow as a technologist and how the individual goes about professional learning and development," Gunderson says. "Additionally, the ability to work in a team and the ability to acknowledge when you don’t know the answer is an essential piece of a great interview."
Don’t confuse "preparation" with "I know all the things"
Know-it-alls tend to not go over well in IT interviews in general. But know-it-all syndrome is especially problematic for sysadmins, since a key part of the role is how you’ll troubleshoot and solve problems when there is no readily available answer. So even if you’ve been doing this for years, don’t let deep experience and expertise convince you there’s nothing left to learn.
"The best responses to these types of interview questions are specific. If you don’t know the answer, tell the interviewer you don’t know, but make sure to include what steps you would take to figure it out," Gunderson says. "Often times, interviewers are looking for how you will tackle a situation you have not come across before. A major concern for interviewers are candidates who not only get the wrong answer, but are unwilling to look outside of their own knowledge for the correct process."
So, in the end, preparing for a sysadmin job interview boils down to making note of every detail in the job description, and then ensuring that you can demonstrate that you understand what's needed for this particular role—given the information they included—and that you're the person to fill that role. When the interviewer(s) see that you fully understand their needs and how you can fill them, you'll be ahead of the game. And finally: practice, practice, practice. Experiment with these technologies, and practice both the interview questions discussed in this article and any others that friends and colleagues have experienced.
Remember, the goal isn't to answer as though you've memorized a script. It's to show that you have a deep knowledge of the system administration space, particularly when related to their needs, and can think on your feet to solve problems as they come. At the very least, you'll leave a good impression and be better prepared for the next interview. Even better, you might get the job.