DevOps Interview Questions

1. What is CI/CD?

2. Containers vs Virtual Machines

3. What is Kubernetes?

4. What is Infrastructure as Code?

5. What is Docker?

6. What is a Docker Image vs a Container?

7. What is a Dockerfile?

8. Blue-Green vs Canary Deployment

9. What is a Kubernetes Pod?

10. Continuous Integration vs Continuous Deployment

11. What is Container Orchestration?

12. What is Monitoring vs Observability?

13. What is Terraform?

14. What is Ansible?

15. What is a CI/CD Pipeline?

16. What is GitOps?

17. What is a Helm Chart?

18. What is a Service Mesh?

19. What is Log Aggregation?

20. What Is Horizontal Pod Autoscaling?

21. What Is a Rolling Update?

22. What Is Immutable Infrastructure?

23. What Is a Kubernetes Secret?

24. What Is Configuration Management?

25. How Do Docker Image Layers and Build Caching Work?

26. What is a Docker Multi-Stage Build?

27. How Do Docker Volumes Persist Data?

28. How Does Docker Networking Work?

29. What is Docker Compose and When Do You Use It?

30. What Are Dockerfile Best Practices?

31. What is a Docker Registry?

32. What is a Container Runtime?

33. Docker vs Podman: What Is the Difference?

34. What Are Distroless Images?

35. What is Docker Image Security Scanning and Why Does It Matter?

36. What is the Difference Between ENTRYPOINT and CMD?

37. What is the Difference Between Docker Bind Mounts and Volumes?

38. What is a Docker HEALTHCHECK and How Does It Work?

39. What is the Docker Build Context and Why Does It Matter?

40. What is a Kubernetes Deployment and How Does It Manage Rollouts?

41. What Are the Different Kubernetes Service Types?

42. What is Kubernetes Ingress and How Does It Route Traffic?

43. What is a Kubernetes ConfigMap and How Is It Used?

44. What is a Kubernetes Namespace and When Should You Use One?

45. What is a Kubernetes DaemonSet?

46. What is a Kubernetes StatefulSet?

47. What is a Kubernetes ReplicaSet?

48. What are Kubernetes Job and CronJob?

49. What are Kubernetes Liveness and Readiness Probes?

50. What are Kubernetes Resource Requests and Limits?

51. What is Kubernetes Node Affinity?

52. What are Kubernetes Taints and Tolerations?

53. What is a Kubernetes Persistent Volume?

54. What is a Kubernetes StorageClass?

55. What is Kubernetes RBAC and How Does It Work?

56. What is a Kubernetes NetworkPolicy?

57. What is a Kubernetes Operator?

58. What is a Custom Resource Definition (CRD)?

59. What is etcd and Why Does Kubernetes Depend on It?

60. What is the Kubernetes Control Plane?

61. What is the Kubelet and What Does It Do?

62. How Does the Kubernetes Scheduler Assign Pods to Nodes?

63. Horizontal Pod Autoscaler vs Vertical Pod Autoscaler

64. How Does the Kubernetes Cluster Autoscaler Work?

65. What is a Kubernetes PodDisruptionBudget?

66. What are Kubernetes Init Containers?

67. What is the Kubernetes Sidecar Pattern?

68. What is a Kubernetes ServiceAccount?

69. What are the Essential kubectl Commands?

70. What are Kubernetes Admission Controllers?

71. Helm Values Files vs Templates: What Is the Difference?

72. What are Kubernetes Pod Security Standards?

73. What are Multi-Container Pod Design Patterns?

74. How Does Service Discovery Work in Kubernetes?

75. What is Jenkins and How Does It Work?

76. What is GitHub Actions and How Do Workflows Run?

77. What is GitLab CI/CD and How Does the Pipeline Model Work?

78. What is Argo CD and How Does GitOps Deployment Work?

79. What is Spinnaker and How Does It Orchestrate Multi-Cloud Deployments?

80. What is Pipeline as Code?

81. What are Build Artifacts in CI/CD?

82. What is a Recreate Deployment Strategy?

83. How Do Feature Flags Support DevOps Practices?

84. What is Trunk-Based Development?

85. What is Release Management in DevOps?

86. How Does Semantic Versioning Work in a DevOps Pipeline?

87. Declarative vs Scripted Jenkinsfile: What Is the Difference?

88. How Does Caching Work in a CI/CD Pipeline?

89. What Are CI/CD Pipeline Triggers and How Do They Work?

90. What is Terraform State and Why Does It Matter?

91. What are Terraform Modules and Why Use Them?

92. Terraform vs CloudFormation: What is the Difference?

93. What is Pulumi and How Does It Differ from Terraform?

94. What are Terraform Workspaces and When Should You Use Them?

95. What Do terraform plan and terraform apply Do?

96. What is an Ansible Playbook?

97. Ansible vs Puppet vs Chef: How Do They Differ?

98. What is HashiCorp Packer and When Would You Use It?

99. What is cloud-init and How Does It Work?

100. What Are Terraform Providers and How Do They Work?

101. What Is a Terraform Remote Backend and Why Use One?

102. What Are Ansible Roles and Why Use Them?

103. What Is an Ansible Inventory and How Does It Work?

104. What Is Idempotency in Infrastructure as Code?

105. What is Prometheus and How Does it Collect Metrics?

106. What is Grafana and How Does it Relate to Prometheus?

107. What is the ELK Stack and How Do Its Components Work Together?

108. What is Distributed Tracing and Why Does it Matter in Microservices?

109. What is Jaeger and How Does it Implement Distributed Tracing?

110. What is OpenTelemetry?

111. What Are Metrics, Logs, and Traces?

112. How Do You Design Effective Alerting?

113. What Are SLIs, SLOs, and SLAs?

114. What is an Error Budget?

115. What is APM (Application Performance Monitoring)?

116. What is Structured Logging and Why Does It Matter?

117. How Does Prometheus Alertmanager Work?

118. What is the Difference Between a Grafana Dashboard and a Panel?

119. What is Log Rotation and Why is it Necessary?

120. What is Auto-Scaling and How Does it Work?

121. What is a Load Balancer and How Does it Work?

122. What is a CDN and How Does it Improve Performance?

123. What is Serverless Computing?

124. What is FaaS (Function-as-a-Service)?

125. AWS vs Azure vs GCP: What Are the Core Differences?

126. What Does "Cloud Native" Actually Mean?

127. What Is the Twelve-Factor App Methodology?

128. What Is Chaos Engineering and Why Do DevOps Teams Use It?

129. What Is Disaster Recovery and How Do RTO/RPO Work?

130. What Backup Strategies Would You Use in Production?

131. How Do You Manage Secrets in a DevOps Pipeline?

132. What is HashiCorp Vault and How Does It Work?

133. What is mTLS and Why Use It Between Services?

134. What is DevSecOps and How Do You Implement It?

135. SAST vs DAST: What Is the Difference?

136. What Are the Key Principles of Container Security?

137. How Does Container Image Vulnerability Scanning Work?

138. What Is Network Segmentation and Why Does It Matter?

139. How Do You Achieve Zero-Downtime Deployment?

140. What are Feature Toggles (Feature Flags)?

141. What is an Artifact Repository?

142. Nexus vs Artifactory: What Are the Differences?

143. What Are the Common Git Branching Strategies?

144. Git Flow vs GitHub Flow: What Is the Difference?

145. Git Rebase vs Merge: What Is the Difference?

146. Monorepo vs Polyrepo: Which Should You Choose?

147. What Is Blue-Green Deployment?

148. What Is a Canary Release Strategy?

149. What Is Shadow Deployment?

150. What Rollback Strategies Would You Use in a Deployment Pipeline?

151. How Do You Safely Run Database Migrations in a CI/CD Pipeline?

152. What is Environment Parity and Why Does It Matter?

153. What is Infrastructure Drift and How Do You Detect and Prevent It?

154. How Does terraform import Work and When Would You Use It?

155. How Do You Approach Cloud Cost Optimization?

156. How Would You Design a Cloud Resource Tagging Strategy?

157. Multi-Cloud vs Hybrid Cloud: What Is the Difference?

158. What Is Edge Computing and How Does It Affect DevOps Practices?

159. What Is a Good Container Image Tagging Strategy?

160. Helm vs Kustomize: What Is the Difference?

161. What Are Kustomize Overlays?

162. GitOps vs Traditional CI/CD: What Is the Difference?

163. What Is Argo Rollouts?

164. What Is Progressive Delivery?

165. Service Mesh: Istio vs Linkerd

166. What is Envoy Proxy?

167. What is an API Gateway?

168. Rate Limiting in Distributed Systems

169. What is the Circuit Breaker Pattern?

170. What is the Bulkhead Pattern in distributed systems?

171. What are Retries and Exponential Backoff, and why use jitter?

172. Sidecar vs Ambassador Pattern: What is the Difference?

173. Kubernetes vs Docker Swarm: How Do They Compare?

174. Nomad vs Kubernetes: How Do They Compare?

175. What are cgroups and namespaces, and how do they power containers?

176. How do container image layers work, and why do they matter for build speed?

177. What is the OCI Image Specification, and why does it matter?

178. What is BuildKit, and how does it improve on the classic Docker builder?

179. What causes cache busting in Docker builds, and how do you avoid it?

180. How Do You Manage SSH Keys Securely in a DevOps Team?

181. What is a Bastion Host and Why Do You Need One?

182. VPN vs VPC Peering: What is the Difference?

183. Kubernetes NetworkPolicies vs Cloud Security Groups: What is the Difference?

184. What is SSL/TLS Termination and Where Should It Happen?

185. How Do You Manage TLS Certificates in a DevOps Pipeline?

186. How Does Let’s Encrypt Certificate Automation Work?

187. How Does DNS Resolution Work Inside Kubernetes?

188. What is CoreDNS and Why Does Kubernetes Use It?

189. What is the Difference Between an Ingress Controller and a Load Balancer?

190. Horizontal vs Vertical Scaling: What is the Difference?

191. What is Statelessness in Microservices and Why Does it Matter?

192. What is a Service Registry and Why Do Microservices Need One?

193. What is Consul and How is it Used in DevOps?

194. What is ZooKeeper Used for in DevOps?

195. What Are Message Queues and Why Do DevOps Teams Use Them?

196. What Is Apache Kafka and How Does It Work?

197. What Is Event-Driven Architecture in DevOps Systems?

198. What Is the Saga Pattern in Distributed Transactions?

199. What Is the Transactional Outbox Pattern?

200. What is Infrastructure Testing and Why Does It Matter?

201. What is Terratest and How Does It Test Infrastructure Code?

202. What is Policy as Code and Why Use It in DevOps?

203. What is Open Policy Agent (OPA) and How Does Rego Work?

204. What is HashiCorp Sentinel and How Does It Enforce Policy?

205. What is Compliance as Code?

206. What are CIS Benchmarks?

207. What is Container Runtime Security?

208. How Does Falco Detect Threats at Runtime?

209. What are Seccomp Profiles in Container Security?

210. AppArmor vs SELinux: What Is the Difference?

211. What Is Container Image Signing With Cosign?

212. What Is an SBOM (Software Bill of Materials)?

213. What Is Software Supply Chain Security in DevOps?

214. What Is the SLSA Framework?

215. What Is a Runbook and Why Does DevOps Rely On Them?

216. How Should an On-Call Rotation Be Designed?

217. Walk Through the Incident Management Lifecycle in DevOps

218. What Makes a Blameless Postmortem Effective?

219. What Is Toil in SRE and How Do You Reduce It?

220. What is Capacity Planning in DevOps?

221. What is Synthetic Monitoring?

222. Blackbox vs Whitebox Monitoring

223. What is Log Sampling and Why Use It?

224. What is the Deployment Frequency Metric?