Common Interview Questions
Easy Questions
What is DevOps?
DevOps is a set of practices that combine software development (Dev) and IT operations (Ops) to shorten the development lifecycle and provide continuous delivery with high software quality. It emphasizes collaboration, automation, and monitoring across all stages of software delivery.
What is Continuous Integration (CI)?
CI is the practice of frequently integrating code changes into a shared repository, often several times a day. Automated builds and tests are triggered to ensure the code is functional and does not break existing functionality.
What are the main benefits of using version control systems like Git?
Version control systems allow developers to track changes to code, collaborate with team members, and revert to previous versions if needed. They improve code quality by enabling code reviews and ensuring traceability of changes.
What is Infrastructure as Code (IaC)?
IaC is the practice of managing and provisioning infrastructure through code rather than manual processes. Tools like Terraform or AWS CloudFormation enable consistent, repeatable deployments.
What is a container?
A container is a lightweight, standalone package of software that includes everything needed to run: code, runtime, system tools, libraries, and settings. Docker is the most widely used containerization platform.
What is a deployment pipeline?
A deployment pipeline automates the steps required to deliver software from source code to production. It typically includes building, testing, and deploying the code.
What is the purpose of monitoring in DevOps?
Monitoring tracks the performance and health of applications and infrastructure. It provides insights into system performance, enabling proactive issue resolution.
What is a rollback in deployment?
A rollback is the process of reverting an application to a previous stable version after a failed deployment. It is an essential feature of modern CI/CD workflows.
What is YAML, and why is it commonly used in DevOps?
YAML (Yet Another Markup Language) is a human-readable data serialization format. It is commonly used in DevOps for configuration files due to its simplicity and readability.
What is the difference between a build and a release?
A build refers to compiling the source code into an executable, while a release is a deployable version of the application, typically made available to end-users.
Medium Questions
What is the difference between Continuous Delivery and Continuous Deployment?
Continuous Delivery ensures that code is always in a deployable state, but deployment to production is done manually. Continuous Deployment goes a step further by automating production deployments whenever the code passes automated tests.
How does a load balancer work, and why is it important?
A load balancer distributes incoming network traffic across multiple servers to ensure availability and reliability. It prevents server overload and improves application responsiveness.
What is Blue-Green Deployment?
Blue-Green Deployment involves maintaining two separate environments: one live (blue) and one idle (green). Updates are deployed to the green environment, and traffic is switched from blue to green after testing. This minimizes downtime and rollback risks.
What is a microservices architecture?
Microservices architecture breaks an application into small, independent services that can be developed, deployed, and scaled separately. It enhances flexibility and scalability compared to monolithic architectures.
What is the role of Kubernetes in DevOps?
Kubernetes is an open-source container orchestration tool that automates deployment, scaling, and management of containerized applications. It helps manage large-scale containerized environments efficiently.
What are the common challenges faced during CI/CD implementation?
Common challenges include managing legacy systems, integrating tools, dealing with unstable tests, and ensuring team buy-in. Proper planning and communication are key to overcoming these hurdles.
What is observability in DevOps?
Observability refers to the ability to understand the internal state of a system by analyzing its outputs, such as logs, metrics, and traces. It is critical for debugging and ensuring system reliability.
What is a service mesh, and why is it useful?
A service mesh is a dedicated infrastructure layer that manages service-to-service communication in microservices architectures. It provides features like traffic management, load balancing, and security.
What is the purpose of artifact repositories like JFrog Artifactory or Nexus?
Artifact repositories store compiled code, binaries, and dependencies to streamline the build and deployment process. They ensure consistency across environments.
How does Ansible differ from Chef or Puppet?
Ansible uses a simple, agentless architecture with YAML playbooks, while Chef and Puppet use agent-based configurations and domain-specific languages. Ansible is often considered easier to set up and use.
Hard Questions
What are canary deployments, and when would you use them?
Canary deployments involve rolling out changes to a small subset of users before deploying to the entire user base. This allows teams to test new features and detect issues in production with minimal impact.
How do you handle secrets management in DevOps pipelines?
Secrets management involves securely storing and accessing sensitive information like API keys or passwords. Tools like HashiCorp Vault, AWS Secrets Manager, or Kubernetes Secrets are commonly used.
What is a monorepo, and what are its pros and cons?
A monorepo is a single repository that stores all code for a project or organization. Pros include simplified dependency management and versioning, while cons include scalability challenges in large repositories.
How do you ensure high availability in a cloud-based application?
High availability can be ensured by using strategies like load balancing, failover systems, distributed data storage, and deploying applications across multiple availability zones or regions.
What is GitOps, and how does it differ from traditional CI/CD?
GitOps is a DevOps practice where Git is used as the single source of truth for declarative infrastructure and application configuration. Changes are automatically applied via pull requests, unlike traditional CI/CD, which may involve manual intervention.
What is the role of chaos engineering in DevOps?
Chaos engineering involves deliberately injecting failures into a system to identify weaknesses and improve resilience. It is a proactive approach to ensure system reliability under adverse conditions.
What is the difference between a hypervisor and a container?
A hypervisor virtualizes hardware to run multiple operating systems, while containers virtualize the operating system to run multiple applications. Containers are more lightweight and faster than virtual machines.
How does distributed tracing work, and why is it important?
Distributed tracing tracks requests as they traverse through microservices, providing insights into performance and bottlenecks. Tools like Jaeger and Zipkin are commonly used for this purpose.
What is a mesh network in Kubernetes, and how is it managed?
A mesh network connects services in Kubernetes clusters, ensuring reliable communication. Tools like Istio or Linkerd manage this network, providing features like traffic routing and encryption.
How would you design a disaster recovery strategy for a critical application?
A disaster recovery strategy involves creating backups, using multi-region deployments, defining recovery time objectives (RTO) and recovery point objectives (RPO), and regularly testing failover procedures.