Stop watching DevOps.
Start doing DevOps.
Practice production incidents, infrastructure changes, deployments, Kubernetes failures, CI/CD problems and cloud operations inside realistic engineering environments.
No credit card to start. 11 scenarios are free.
- Scenarios
- 90
- Categories
- 9
- Graded on
- Environment state
Production API returning 502 after deployment
The checkout API began returning intermittent 502 responses approximately 15 minutes after the latest production deployment. Customer support reports 17 failed checkout attempts in the last 20 minutes.
$ curl -i http://localhost/api/checkout HTTP/1.1 502 Bad Gateway $ ssh api-prod-01 $ systemctl status checkout-api ● checkout-api.service — failed Status: "main process exited, code=exited, status=2" $ sudo systemctl start checkout-api $ exit $ curl -i http://localhost/api/checkout HTTP/1.1 200 OK
What is DevOps Arena
A job simulator, not a course
You are onboarded as an engineer at NexaCommerce, a mid-size commerce platform. Work arrives as tickets and incidents. You investigate, fix, and submit — and your work is graded by inspecting the environment you leave behind, not by a quiz.
Nobody tells you the answer
A ticket describes a symptom and a business impact. The cause is somewhere in the environment, and the logs contain evidence rather than instructions.
Any valid fix passes
Evaluation reads the resulting state — is the service running, does the endpoint answer, has the error rate recovered. It never compares against a stored answer, so an unanticipated route works.
Restarting it does not help
A service whose config does not parse will not start however many times you try. The environment is a state machine, so the fix has to be real.
How it works
The loop
- 01
Work arrives
A ticket or incident lands in your queue with a priority, an SLA and a business impact.
- 02
Environment starts
An isolated estate boots in under a second — hosts, services, containers, a cluster, metrics and logs.
- 03
You fix it
SSH between hosts, read logs, inspect services, change configuration, deploy, roll back, verify.
- 04
You are graded
Checks inspect the environment state and return a scored report with what passed, what did not, and why.
Scenario library
Nine categories of real work
Every scenario is a distinct failure with its own environment, evidence and grading criteria. None of them are variations of the same task.
Incident Response
10Production outages with a customer-visible symptom, a cause that is not where the symptom appears, and a postmortem to write.
Linux
10Services that will not start, permissions that block a deploy, disks and inodes filling up, ports already taken.
Docker
10Crash loops, oversized images, missing health checks, credentials in environment variables, and container networking.
Kubernetes
10Rollouts that never complete, services with no endpoints, OOM-killed pods, unschedulable workloads and RBAC.
CI/CD
10Pipelines that fail for real reasons: dependency breakage, missing credentials, gates that fail open, no rollback path.
Terraform
10Drift, state locks, unmanaged resources, force-replacement plans, and the module versioning that makes builds reproducible.
AWS
10Security groups, IAM, encryption, scaling groups, load balancer health and VPC routing, through the CLI.
Observability
10Alerts that do not fire, dashboards that stay green during outages, SLOs, error budgets and runbooks.
Security
10Exposed credentials, open ports, privileged containers, vulnerable dependencies, and responding to a leak.
Evaluation
Graded like a code review
Every attempt produces a report against a fixed rubric, with a per-check explanation of what was observed.
Rubric
Sample feedback
FAQ
Questions engineers actually ask
Are these real cloud environments?
The environments are a deterministic simulation of a production estate — filesystem, processes, systemd, Docker, Kubernetes, Terraform and AWS state. That is deliberate: grading has to be reproducible, and a scenario that passes or fails depending on image pull latency is a broken scenario. Docker and Kubernetes providers exist behind the same interface for deployments that want real infrastructure.
Do I need to already know DevOps?
Yes. This assumes you know what systemctl, kubectl and terraform are. It will not explain what a container is. It gives you a failing production system and expects you to work.
How is my work graded?
Checks inspect the resulting environment: is the service running, is the port listening, does the endpoint answer, has the metric recovered, does the config contain what it needs. Nothing compares your commands against an expected transcript.
What if I solve it a different way?
You pass. The checks assert properties of the finished environment, so any route that reaches a correct end state is a correct route.
Can I use hints?
Yes, and they cost points. They are progressive and time-gated — the first unlocks after a few minutes, and each one nudges toward a method of investigation rather than naming the answer.
Is my work saved?
Every attempt records its commands, hints, documents, evaluation and score. You can review any past attempt and see exactly what you did.
The next incident will not wait for you to be ready.
Practise the work before it is your production system and your Saturday.