Becoming a DevOps engineer: skills and career
Summary: this lesson gives a realistic roadmap to become a DevOps engineer — the skills actually expected, a six-month learning plan, the single project that convinces more than ten certifications, the salary orders of magnitude, and the certifications worth the investment.
1. The skills actually expected
The point beginners underestimate the most: networking. DNS, HTTP, TLS, firewalls, routing. It is what breaks in production, it is what is asked in technical interviews, and it is what almost nobody reviews. Someone able to explain why a TLS certificate is rejected, or to diagnose a failing DNS resolution, stands out immediately.
A note about job offer lists: an ad demanding fifteen technologies describes a wish, not a requirement. If you tick the "essential" boxes and two or three "in high demand" ones, apply.
2. The human skills that make the difference
Skill 2 is the one technical interviews are decided on. The typical question is: "a user reports that the site is slow, what do you do?". What is being evaluated is not your knowledge of tools, but your method: where do you start, how do you narrow the scope, how do you verify your hypotheses.
Skill 1 is the one that accelerates a career the most. Two engineers of equal technical level, one of whom can write clearly, will not have the same trajectory — because the latter influences decisions and trains others.
3. The six-month learning plan
The rule that makes this plan effective: one deliverable per month. Reading documentation without producing leads nowhere. An imperfect but working project teaches you infinitely more than ten tutorials followed passively.
Do not skip month 2. It is the one people abandon because it is less spectacular than Kubernetes — and it is the one that will set you apart in a technical interview.
4. The project that convinces
Point 8 is the one that makes the difference in an interview, and almost nobody takes care of it. A technical recruiter is not trying to verify that you can type commands — they want to know whether you think. Documentation that explains "I chose PostgreSQL over MongoDB because my data is highly relational" demonstrates far more than a perfect configuration file.
Point 6 is an excellent conversation topic: mentioning that you have tested your rollback immediately places you above the average candidate, because most production teams do not do it.
5. Salaries — orders of magnitude
Indicative values for France, in gross annual salary, highly variable depending on the region, sector and company size.
| Level | Experience | Indicative range |
|---|---|---|
| Junior | 0 to 2 years | €35,000 to €45,000 |
| Mid-level | 2 to 5 years | €45,000 to €60,000 |
| Senior | 5 to 8 years | €60,000 to €80,000 |
| Expert or senior SRE | 8 years and up | €75,000 to €95,000 |
| Architect or platform lead | 10 years and up | above €90,000 |
The factors that make these amounts vary:
- The region — the Paris region is generally 15 to 25% above other regions.
- The sector — finance, insurance and large technology companies pay more.
- The type of company — product companies and specialized consulting above generalist service providers.
- International remote work — working remotely for a foreign company changes the scales entirely.
A point to know about negotiation: cloud skills and the ability to reduce infrastructure costs are particularly valued, because they translate directly into measurable savings. Being able to say "I cut the cloud bill by 30%" is a powerful negotiation argument.
6. The certifications worth the investment
The particular value of the CKA comes from its format: the exam is entirely hands-on, in a terminal, with a time limit. You cannot pass it by memorizing definitions. That is exactly why technical recruiters take it seriously.
The correct order matters: practice first, certify next. A certification earned by memorization will get you past the automatic recruitment filter, then the technical interview will reveal the lack of practice — an unpleasant and avoidable situation.
7. Career stages
The step from mid-level to senior is the most misunderstood. It is not decided by the number of tools mastered, but by a change in the nature of your impact: you stop being evaluated on what you produce alone, and you start being evaluated on what you enable others to produce. Documenting, training, simplifying, deciding — those are the activities that make a senior profile.
8. Succeeding in a DevOps interview
Question 5 is where candidates needlessly penalize themselves. Many try to present an incident where they solved everything brilliantly. An experienced recruiter far prefers an honest answer: "I caused an outage by making this mistake, here is how we detected it, and here is the guardrail we put in place afterwards". That demonstrates maturity and a learning culture — exactly what DevOps looks for.
Question 2 eliminates many candidates and it is entirely reviewable. Take an hour to build a structured answer: DNS resolution, TCP connection establishment, TLS negotiation, HTTP request, response, rendering. It is a profitable investment.
Remember in 30 seconds
- Essential: Linux, Git, a scripting language. In high demand: Docker, CI/CD, one cloud, networking.
- Networking is the most underestimated skill — DNS, HTTP, TLS. It is what breaks in production and what is asked in interviews.
- Job offers describe a wish. If you tick the essentials and two or three others, apply.
- Human skill number one: writing clearly. It multiplies the effect of your technical work.
- What is decided in a technical interview: your diagnostic method, not your tool catalog.
- Six-month plan: Linux and Git → scripting and networking → Docker → CI/CD and cloud → Terraform and observability → Kubernetes. One deliverable per month.
- A single complete project is worth more than ten certifications — and document your choices, not your commands.
- Salaries: roughly €35–45k junior, €45–60k mid-level, €60–80k senior, above that for expertise.
- The CKA is valued because it is 100% hands-on. Practice first, certify next.
- Going senior = your impact comes from what you enable others to do.
- In an interview, own a real mistake and explain what it taught you. It is very well received.