DevOps Engineer
What the work looks like, the stacks behind the title, what each level means and the training that helps, then how interviews run and how to prepare for each step.
What a DevOps engineer actually does
An engineer who automates how software is built, tested, deployed and run, so that teams can ship often and safely.
A DevOps engineer builds and runs the pipelines and the infrastructure that development teams rely on. They automate builds, tests and deployments with tools such as GitHub Actions, GitLab CI or Jenkins, and they manage the infrastructure as code with Terraform, OpenTofu or Ansible.
They run containers on Kubernetes, deploy with GitOps tools such as Argo CD, manage secrets and set up the monitoring that tells teams when something goes wrong. They often take part in on-call and incident handling.
More and more teams also work with AI coding tools such as Claude Code, Cursor or GitHub Copilot, and expect engineers to use them with judgment.
- Building or fixing a CI/CD pipeline
- Changing infrastructure with Terraform and code review
- Helping a team deploy a new service on Kubernetes
- Handling an incident or a failed deployment
- Improving monitoring, alerts or secrets management
The same title, very different stacks
Most DevOps searches are defined first by the way the company runs its infrastructure, then by the ground every DevOps engineer shares.
What each level means in practice
Titles vary from one company to the next. What changes from one level to the next is the scope you own and the decisions you take.
- Works on pipelines designed by a senior engineer
- Learns the infrastructure, the tools and the teams
- Writes infrastructure code with review
- Builds and runs pipelines on their own
- Handles incidents and failed deployments
- Works directly with development teams
- Designs the delivery and infrastructure of a product
- Takes choices on tools, cost and security
- Mentors other engineers and leads code reviews
- Sets the infrastructure standards across teams
- Leads choices on platforms and practices
- Writes the design documents others build on
The paths into the role, and what really counts
Companies look first at pipelines and infrastructure you have built and run in production. Education and certifications help most early in a career, or to change field.
- Engineering school or master's in computer scienceThe most common path in France, and often expected by large companies.
- University degree in computer scienceThe most common path in the US, at bachelor's or master's level.
- System administration firstMany DevOps engineers start as system administrators and move to automation.
- Development firstBackend developers who like infrastructure also move into the role.
Our view: for this role, certifications help, and a pipeline or an infrastructure you built and can walk through counts even more.
A conversation with a senior tech recruiter
Your first interview is with one of our senior tech recruiters, who knows the role, the stacks and the levels in this guide. The conversation covers your own work through real examples, and the technical exercises come later, with the company. Before the call, we send you the six themes we will cover so you can prepare your examples.
- What you owned yourselfThe pipelines, infrastructure or deployments you were responsible for, and your own part in the team's work.
- Your environment and its constraintsTeam size, cloud, security rules, legacy systems or deadlines: what shaped your technical choices.
- The decisions you madeWhich tools, which deployment model and which level of automation, the options you compared and the reasons for your choice.
- The impact of your workWhat changed thanks to your work, with numbers when you have them: deployment frequency, lead time, costs or incidents.
- How you work with other teamsYour work with development teams, security and operations, and how you settle a disagreement.
- What you want nextThe kind of infrastructure, scale and scope you are looking for in your next role.
- Pipelines teams rely on
- Quality of infrastructure as code
- Incident handling
The same ground for every candidate. For a given role, every candidate answers the same final questions, built with the hiring manager around what the role really needs.
Ready for the next steps. After our call, we tell you how the company runs its interviews, who you will meet at each step and what each step is meant to assess.
What the company will assess, step by step
Each company runs its own process, and we walk you through its steps before you start. DevOps processes often combine the steps below, and the depth expected at each step grows with your level.
- A hands-on exerciseA pipeline to write, Terraform code to fix or a container that fails to start, live or as a take-home.
- A design discussionA delivery or infrastructure setup to design for a team, from the code to production.
- A troubleshooting scenarioA failed deployment or an incident, and how you find the cause step by step.
- Meeting the manager and the teamHow you work, how you take decisions with others and what the team expects in your first months.
- ConfirmedYou solve the exercise cleanly, explain each step in simple words and think about security and rollbacks.
- SeniorYou lead the design, weigh speed, cost and safety, and point out risks and limits before you are asked.
- Staff and PrincipalYou run most of the interview as a peer, think about the whole platform and connect the design to the needs of several teams.
How to prepare as a DevOps engineer
Practical advice for each step of a DevOps process, from the way you introduce yourself to the questions you ask at the end of each interview.
Start with the pipelines and infrastructure you worked on, their scale and your part in them. Mention your stack in one sentence, then close with what you want next.
For each one, prepare the context, the constraints, your decision, the options you set aside, the result and what you would change today. Say "we" for the team and "I" for your own part.
In a troubleshooting scenario, explain each check you make and why, from the logs to the metrics, before you propose a fix.
Prepare the deployment frequency, the lead time, the incidents and the costs of the systems you ran.
Prepare one incident you handled, with what you saw, what you did, what you changed after and how you shared it.
Rules on AI coding assistants differ from one company to the next, and sometimes from one step to the next. Ask before each step, and when they are allowed, explain what you ask the tool and how you check its output.
- Walk us through a CI/CD pipeline you built.
- A deployment fails in production. What do you do?
- How do you manage secrets in your pipelines?
- How do you organise Terraform code for several teams?
- Which CI/CD and infrastructure tools does the team use?
- How often do teams deploy to production?
- Who is on call, and how often?
- How do DevOps and development teams share the work?
- Which projects are planned for the infrastructure this year?
- How does the team use AI coding tools day to day?
Where DevOps engineers come from, and where they go
The roles people most often hold before this one, and the ones they most often move to.
Many DevOps engineers start as system or network administrators.