Advanced Devops Interview Question and Answer

1. What is Infrastructure as Code (IaC)?

Infrastructure as Code (IaC) is a DevOps practice where infrastructure is provisioned using code. It allows for version control, automated deployment, and consistency across environments. Tools like Terraform, Ansible, and CloudFormation are commonly used. IaC reduces manual configuration and improves infrastructure scalability and reliability.

2. Explain the difference between blue-green and canary deployment.

Blue-green deployment involves two environments: one live and one standby. You switch traffic to the new version after testing it in the standby environment. Canary deployment gradually routes a small portion of users to the new version. It allows you to monitor impact before full-scale deployment, reducing risk.

3. What is the role of CI/CD in DevOps?

CI/CD stands for Continuous Integration and Continuous Delivery/Deployment. It ensures that code changes are automatically tested and deployed. CI automates the building and testing of code on every change. CD automates delivery or deployment to production, enabling rapid release cycles.

4. How does containerization help in DevOps?

Containers package applications with their dependencies in isolated environments. They ensure consistency across development, testing, and production systems. Tools like Docker simplify container creation and management. Containers help in microservices architecture and improve deployment speed and scalability.

5. What is the use of Configuration Management tools in DevOps?

Configuration management tools manage system configurations in an automated way. They help maintain consistency across infrastructure and reduce manual errors. Examples include Ansible, Puppet, and Chef. They enable version control and quick rollback of configurations.

6. How is GitOps different from DevOps?

GitOps is a subset of DevOps that uses Git as a single source of truth. It automates infrastructure and application deployment using Git workflows. GitOps enhances transparency, auditability, and declarative configuration. It integrates tightly with Kubernetes for managing cluster states.

7. What is observability and why is it important?

Observability refers to the ability to understand internal system states from outputs. It includes metrics, logs, and traces to monitor applications and infrastructure. Observability helps detect and debug production issues faster. Tools include Prometheus, Grafana, ELK stack, and Jaeger.

8. Describe a typical CI/CD pipeline.

A typical pipeline includes code commit, build, test, and deploy stages. Code is pushed to a repository triggering automated builds. Unit and integration tests run before deploying to staging or production. Tools like Jenkins, GitLab CI, and CircleCI are commonly used.

9. What are the benefits of using Kubernetes?

Kubernetes automates deployment, scaling, and management of containerized apps. It provides service discovery, self-healing, and load balancing. K8s abstracts infrastructure complexities from the application layer. It supports hybrid and multi-cloud environments with robust orchestration.

10. What is the difference between a monolith and microservices architecture?

Monoliths are single-tiered applications where all components are tightly coupled. Microservices split functionality into independently deployable services. Microservices improve scalability, agility, and fault isolation. They are typically containerized and communicate over APIs or messaging queues.

11. What are some common DevOps anti-patterns?

Treating DevOps as a role instead of a culture or practice. Manual configuration and lack of automation. Siloed teams that lack collaboration between dev and ops. Neglecting monitoring, testing, and security in the pipeline.

12. Explain immutable infrastructure.

Immutable infrastructure means once deployed, servers are never modified. Changes are made by replacing servers rather than updating them. This approach reduces configuration drift and simplifies rollbacks. Used commonly with containers and cloud-based environments.

13. What is the difference between Ansible and Terraform?

Ansible is a configuration management tool focused on procedural tasks. Terraform is an infrastructure provisioning tool using declarative syntax. Terraform manages cloud resources using providers and state files. Ansible works well for software configuration after provisioning.

14. How do you manage secrets in DevOps?

Secrets should never be hardcoded or committed to version control. Use secret management tools like HashiCorp Vault, AWS Secrets Manager, or Sealed Secrets. Kubernetes secrets and encrypted environment variables are also common. Ensure access control and audit trails for secret usage.

15. What is shift-left testing?

Shift-left testing means performing testing earlier in the development cycle. It helps identify bugs sooner, reducing cost and improving quality. It involves unit testing, static code analysis, and integration testing. It integrates testing into CI/CD pipelines for continuous feedback.

16. What are feature flags?

Feature flags allow enabling/disabling features without deploying new code. They help in testing new features in production with controlled exposure. They support A/B testing and reduce rollback risks. Tools include LaunchDarkly, Unleash, and Flagger.

17. Explain chaos engineering.

Chaos engineering involves intentionally introducing faults to test system resilience. It helps uncover weaknesses in distributed systems before real incidents. Tools include Chaos Monkey and Gremlin. It promotes designing robust systems that can withstand failures.

18. What are some metrics you monitor in a DevOps pipeline?

Build success/failure rate and deployment frequency. Mean time to recovery (MTTR) and change failure rate. Infrastructure usage, application latency, and error rates. User experience and availability metrics from monitoring tools.

19. How does DevSecOps differ from DevOps?

DevSecOps integrates security practices into the DevOps workflow. It emphasizes security automation from code to production. Includes static/dynamic analysis, dependency scanning, and policy enforcement. It ensures security is everyone’s responsibility, not just a separate team.

20. What is the role of containers in microservices?

Containers encapsulate microservices with all dependencies. They provide isolation and portability across environments. They enable independent deployment and scaling of services. Tools like Docker and Kubernetes manage container lifecycles.

21. How do you ensure high availability in DevOps?

Use load balancers and redundant infrastructure to avoid single points of failure. Implement health checks and failover strategies. Automate scaling and recovery using orchestration tools. Monitor uptime and error rates to ensure continuous availability.

22. Explain Git branching strategies used in DevOps.

Common strategies include Git Flow, GitHub Flow, and trunk-based development. Git Flow uses feature, release, and hotfix branches. GitHub Flow focuses on short-lived branches with PRs to main. Trunk-based development promotes direct commits to main with CI gates.

23. What is a service mesh?

A service mesh manages service-to-service communication in microservices. It provides observability, traffic control, and security without changing code. Istio, Linkerd, and Consul are popular service mesh tools. It works alongside Kubernetes and supports zero-trust networking.

24. What is the purpose of a build artifact repository?

It stores compiled packages, binaries, and dependencies. Enables reuse of build outputs and consistent deployments. Examples include JFrog Artifactory, Nexus, and GitHub Packages. Helps in caching, versioning, and auditability of builds.

25. What is the 12-factor app methodology?

It is a set of best practices for building scalable web applications. Includes codebase, config, backing services, and logs. Focuses on portability, automation, and clean dev/prod parity. Supports continuous deployment and cloud-native design principles.

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Advanced Devops Interview Question and Answer