As a hiring manager of systems administrators (sys admins) for the past three years, I know the kind of candidates I'm looking for to join my open source team. My responsibility, of course, is to try to hire the best and brightest from around the world. The candidate's responsibility is to tell me what they've done and how, and what they want their future to look like. I am also looking for that spark. That thing that tells me this candidate is dedicated to the success of open source.
I start my interviews with, "Thanks for taking the time to meet with us. Don’t be nervous, and remember to breathe." An interview is about finding the right match on both sides, so intimidation is a bad practice on my end, but it should also be a bad sign to the candidate about the culture of a company if they are made to feel scared.
At Red Hat, a candidate typically interviews first with a recruiter, then with a hiring manager, and finally moves on to a panel composed of potential future team members. In my role, it's my responsibility to protect my team's time and only ask for it if I think a candidate would be a great fit. In terms of fit, I look for culture fit, team fit, and community fit. Community and collaboration are both at the heart of Red Hat, and at the heart of how our teams interact.
To be a positive impact on a collaborative team within the open source community, a candidate needs to be able to communicate well, and not just with the right words but also with their actions. Candidates should demonstrate mutual respect for their teammates ideas, opinions, and suggestions.
From my point of view, and I tell my team this all the time, I can teach someone how to provision a host, or how to deploy an application very easily. But, I cannot so easily teach them how to be cordial, polite, and easy going with others. This is not to say that technical skills aren’t important—of course they are—but the vessel of the knowledge is more important than the knowledge itself.
I am also interested in a candidate's level of curiosity. I want to hire sys admins who won't likely get bored with the everyday, mundane tasks asked of their job. Good candidates will take responsibility for that and strive to keep their job fun—like, looking for ways to automate tasks in order to spend more time learning a new technology (i.e. Docker or OpenStack).
Being able to include your work on an open source project (previous or current) on your resume is great. It shows drive and experience, and helps you stand out. An additional thing I look for is some kind of certification (for example, RHCE or Red Hat Certified Engineer). That tells me a candidate is serious, willing to go the extra mile, and works well under pressure.
Before I finish an interview, I always ask the candidate, "Tell me something that really makes you mad at work." What would you say?