13.2 Interview Preparation: DevOps Engineer

Note

Interview are popularity contest you don’t have to know everything but you have to make a good impression.

Who are you?

Note

Most of us, when asked to talk about ourselves, we tend to ramble on and on about our lives and careers. This is a mistake. The interviewer is not interested in your life story; they are interested in what you can do for them and their company. So, when asked to talk about yourself, you should focus on your professional skills and accomplishments, not your personal life.

Question: Who are you? Answer: I’m Claudiu, DevOps/Data engineer with almost 15 years of experiense, focused on make data and software development stupid and easy to you. My goal is to automate everything and challange the status quo, while keeping the business running, the customers happy, and empowring the team to take data driven decisions.

But, this feels fake. Because it is. The entire process is fake. You’re an actor at his casting aution.

By being prepared you can always stir the conversation to your advantage.

Junior DevOps Engineer

Expectations from a Junior DevOps Engineer:

  • Basic understanding of DevOps principles and practices

  • Familiarity with CI/CD tools and processes

  • Basic knowledge of cloud platforms and infrastructure

  • Basic understanding of networking and security concepts

  • Basic scripting and automation skills

So, it expected to know what we learned in this course.

  • Question: What is DevOps and how does it improve collaboration between development and operations teams?

    Answer: DevOps is a set of practices that combines software development (Dev) and IT operations (Ops) aimed at shortening the systems development life cycle and providing continuous delivery with high software quality. It improves collaboration by promoting a culture of shared responsibilities, transparency, and communication between the two teams.

  • Question: What experience do you have with using version control systems?

    Answer: I have experience using Git for version control. I am familiar with basic commands like git commit, git push, git pull, and git merge. I’ve also used branching strategies like feature branching to manage code development in a team environment.

  • Question: Can you explain what continuous integration is and why it’s important?

    Answer: Continuous integration (CI) is the practice of automating the integration of code changes from multiple contributors into a single software project. It’s important because it allows teams to detect problems early, improve quality, and reduce the time it takes to validate and release new software updates.

  • Question: What tools have you used for automating deployments?

    Answer: I have used Jenkins to create CI/CD pipelines for automating code deployments. Additionally, I’ve had some exposure to using Docker for containerization, which helps in ensuring consistent environments from development through to production.

  • Question: How do you approach troubleshooting a service that is not working as expected?

    Answer: My approach is to start with checking the service logs to look for any error messages or warnings. If that doesn’t provide a solution, I’ll verify the configuration files and network connectivity. If the issue persists, I’ll search online for similar problems or reach out to my team for assistance.

  • Question: What is infrastructure as code (IaC) and have you had any experience with it?

    Answer: IaC is the management of infrastructure (networks, virtual machines, load balancers, and connection topology) in a descriptive model, using the same versioning as DevOps team uses for source code. I have some experience using Terraform in lab settings to create and manage cloud resources.

  • Question: Can you explain the concept of containerization and its benefits?

    Answer: Containerization involves encapsulating an application and its environment into a container that can run on any infrastructure. This provides benefits like consistency across multiple development, testing, and production environments, and it simplifies CI/CD pipelines.

  • Question: How do you ensure you are up-to-date with the latest technology trends in DevOps?

    Answer: I follow industry blogs, attend webinars, and participate in community forums. I also experiment with new tools in personal projects or sandbox environments to get hands-on experience.

  • Question: What is the purpose of a monitoring solution in a DevOps environment?

    Answer: Monitoring solutions in DevOps provide real-time data and alerts about the health of applications and infrastructure. This allows teams to quickly detect and respond to issues, ensuring high availability and performance.

  • Question: How would you describe the role of automation in a DevOps environment?

    Answer: Automation in DevOps is critical for reducing manual overhead, minimizing errors, ensuring consistency, and speeding up processes from code development to deployment and infrastructure management.

Mid-Level DevOps Engineer

Expectations from a Mid-Level DevOps Engineer:

  • Strong understanding of DevOps principles and practices

  • Experience with CI/CD tools and processes, best practices, and patterns

  • Experience with cloud platforms and infrastructure

  • Strong understanding of networking and security concepts

  • Strong scripting and automation skills

  • Question: How do you manage configuration drift in a distributed system?

    Answer: I use configuration management tools like Ansible and Puppet to maintain system consistency. These tools ensure that all systems are configured to a defined state and can automatically correct any drift detected.

  • Question: Describe how you would set up a secure CI/CD pipeline.

    Answer: To set up a secure CI/CD pipeline, I would integrate security scanning tools to check for vulnerabilities in the code and dependencies. I would also enforce role-based access controls on the CI/CD tools, use secure artifacts repository, and ensure that deployment scripts adhere to security best practices.

  • Question: Can you discuss your experience with cloud platforms, such as Azure or AWS?

    Answer: I have experience deploying and managing applications on both Azure and AWS. This includes working with services like EC2, S3, RDS, Azure VMs, Azure Blob Storage, and Azure SQL. I’ve also set up VNet and VPC configurations for network isolation and security.

  • Question: How do you handle database changes in a DevOps workflow?

    Answer: Database changes are handled through version-controlled migration scripts that are applied as part of the deployment pipeline. I use tools like Flyway or Liquibase for database versioning and ensure that rollback scripts are available in case of a failed deployment.

  • Question: Describe a time when you improved a process in your previous DevOps role.

    Answer: In my previous role, I improved our deployment process by implementing blue-green deployments. This reduced downtime and provided a quick rollback strategy if any issues were detected in production.

  • Question: How do you approach cost optimization for cloud resources?

    Answer: I use a combination of reserved instances for predictable workloads, auto-scaling to adjust to demand, and monitoring tools to identify underutilized resources. Additionally, I review billing reports to find cost-saving opportunities regularly.

  • Question: What strategies do you use for maintaining zero downtime deployments?

    Answer: I use strategies like canary releases, feature toggles, and rolling updates. These allow us to introduce new changes gradually and monitor their performance before a full rollout.

  • Question: How do you ensure compliance with regulatory requirements in your DevOps practices?

    Answer: I ensure compliance by automating security checks and audits within the pipeline, using infrastructure as code to maintain a clear change history, and implementing strict access controls and logging.

  • Question: What’s your experience with scripting and automation?

    Answer: I have written numerous scripts in Python and Bash to automate routine tasks such as deployments, monitoring, and system health checks. I also have experience with Ansible for automation of provisioning and configuration management.

  • Question: How do you manage team collaboration in a DevOps culture?

    Answer: I promote open communication, encourage sharing of knowledge through documentation and pair programming, and use collaborative tools like Git for version control and Slack for communication.

Senior DevOps Engineer

Expectations from a Senior DevOps Engineer:

  • Understand of business goals and how DevOps can help achieve them

  • Ability to present and advocate for DevOps best practices

  • Knowledge of the latest technologies, tools, trends, best practices, patterns and security issues

  • Having broad experience with different projects and how to solve the same problem in multiple ways

  • Being expert with designing and implementing CI/CD pipelines, while keeping security and compliance in mind

  • Expert in all the environments,baremetal, virtual machines, container and cloud, including cost optimization, security, resilience, scalability, and compliance.

  • Question: What methodologies do you employ to ensure code quality in your team’s deliverables?

    Answer: To ensure code quality, I advocate for test-driven development (TDD), code reviews, and pair programming where appropriate. I also integrate static code analysis tools into our CI/CD pipeline and encourage comprehensive unit and integration tests. Regular refactoring sessions are scheduled to maintain code health.

  • Question: Describe a complex system you have worked on. What was your role, and how did you contribute to the project’s success?

    Answer: I worked on a distributed e-commerce system designed to handle high traffic during peak sales periods. As a senior developer, I contributed to the system’s architecture and led the backend team in implementing microservices that improved scalability and performance. My role also involved mentoring junior developers and ensuring our codebase was both efficient and maintainable.

  • Question: How do you stay updated with the latest development technologies and trends?

    Answer: I regularly read tech blogs, participate in developer forums, attend webinars, and contribute to open-source projects. I also take online courses to enhance my skills and attend local meetups and conferences to network with other professionals and exchange knowledge.

  • Question: Can you discuss a time when you had to make a significant technical decision, and how you approached it?

    Answer: In my previous role, I had to decide on the database technology for a new feature we were developing. I conducted a thorough comparison of SQL and NoSQL databases considering factors like data structure, scalability, and the complexity of queries we’d be running. After prototyping with both types, I chose a NoSQL database because it best met our needs for scalability and speed.

  • Question: What strategies do you use to effectively lead and mentor less experienced developers?

    Answer: I believe in leading by example, so I ensure my work reflects best practices. I hold regular one-on-one sessions to provide personalized guidance and feedback. I also organize code review sessions to foster a culture of learning and collective code ownership among the team.

  • Question: How do you handle disagreements about technical approaches within your team?

    Answer: When disagreements arise, I encourage open discussions where each developer can present their perspective and rationale. I ask questions to clarify points and often suggest we prototype different approaches when feasible. The goal is always to reach a consensus that aligns with the project’s objectives and technical requirements.

  • Question: In what ways have you contributed to the improvement of the software development lifecycle (SDLC) in your current or past roles?

    Answer: I’ve contributed by implementing CI/CD pipelines to shorten release cycles, advocating for automated testing to catch bugs early, and introducing code quality tools. Additionally, I’ve worked with product managers to refine our Agile practices, making our SDLC more efficient and responsive to change.

  • Question: How do you ensure that your application designs meet both functional and non-functional requirements?

    Answer: I start with a thorough analysis of requirements and create design documents that outline how the application will meet these needs. For non-functional requirements, such as performance and scalability, I use benchmarks and prototypes to validate designs. I also solicit feedback from stakeholders to ensure all criteria are met.

  • Question: Can you explain a situation where you had to optimize a piece of code for better performance? What steps did you take?

    Answer: In a past project, a module I was working on was not performing optimally under load. I used profiling tools to identify bottlenecks and found that the issue was due to unnecessary database queries in a loop. By refactoring the code to batch the queries and reduce the overall number, I significantly improved the performance.

  • Question: How do you balance technical debt with new feature development?

    Answer: Balancing technical debt and new features is about prioritization and understanding impact. I work with the product team to understand the business value of new features and weigh that against the cost of maintaining and improving existing code. We schedule regular refactoring and debt reduction sprints to ensure that the codebase remains healthy and doesn’t hinder future development.