DevOps Cheat Sheet 2026

The 30 highest-yield DevOps facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is a post-mortem (or post-incident review) in DevOps? → A blameless analysis of an incident to identify root causes and prevent recurrence
2. Which Git branching strategy uses long-lived branches named 'main', 'develop', 'release', and 'hotfix'? → Gitflow
3. What is the difference between 'git fetch' and 'git pull'? → git fetch only downloads remote changes; git pull downloads and merges them
4. In Git, what does a 'merge conflict' indicate? → Two branches changed the same lines and Git cannot auto-resolve them
5. What is the ELK Stack? → Elasticsearch, Logstash, and Kibana — a log aggregation, search, and visualization stack
6. What does a Kubernetes Deployment object manage? → The desired state and rolling updates of a set of Pods
7. In Kubernetes, what is the role of a 'liveness probe'? → Detects when a container should be restarted because it is unhealthy
8. Which metric measures how frequently code is deployed to production in a CI/CD context? → Deployment frequency
9. What does a Kubernetes HorizontalPodAutoscaler (HPA) do? → Automatically scales the number of Pods based on CPU or custom metrics
10. What is the function of the Kubernetes Horizontal Pod Autoscaler (HPA)? → Automatically scales the number of Pod replicas based on CPU/memory metrics
11. 3. Which of the following best describes DevOps? → A cultural and professional movement
12. What does the command 'git rebase -i HEAD~3' accomplish? → Interactively edits the last 3 commits
13. What does the term 'idempotent' mean in the context of configuration management tools like Ansible? → Applying the same operation multiple times yields the same result
14. Which practice ensures that every code change passes automated tests before being merged? → Continuous Integration
15. 17. What exactly is the DevOps process loop? → Plan, code, build, test, deploy, operate, monitor, plan
16. What does 'container orchestration' mean? → Automated management of container deployment, scaling, networking, and health
17. 2. What is one of The Second Way's goals? → Shortening feedback loops
18. What is Azure DevOps? → A Microsoft platform offering CI/CD pipelines, repos, boards, and artifact management
19. Which Docker command removes all stopped containers, unused images, networks, and build cache? → docker system prune
20. What is the primary purpose of a Docker container? → To package an application with its dependencies into an isolated runtime environment
21. What is the purpose of 'feature flags' in continuous delivery? → Enabling or disabling features at runtime without redeploying
22. What is a DaemonSet in Kubernetes? → Ensures a copy of a Pod runs on every (or selected) node in the cluster
23. What is a Kubernetes resource 'limit' vs. 'request'? → Requests are the guaranteed minimum resources; limits are the maximum a container can use
24. What is the purpose of `terraform plan`? → Shows what changes Terraform will make without actually applying them
25. In a pipeline, what is a 'gate' or 'approval step' used for? → Requiring a condition or human sign-off before promoting to the next stage
26. What is the recommended approach when a long-lived feature branch falls significantly behind the main branch? → Rebase the feature branch onto the latest main to incorporate updates
27. What is etcd in a Kubernetes cluster? → A distributed key-value store that holds all cluster state and configuration
28. What does a 'rolling update' deployment do? → Gradually replaces old instances with new ones to avoid downtime
29. 9. Which DevOps practice backs up The Second Way? → Peer review of production changes
30. What is a multi-stage Docker build used for? → Reducing the final image size by discarding build tools in intermediate stages