Interview Questions - Position: DevOps Engineer

• Have you ever disagreed with a decision your management team made? How did you handle it?

• How do you respond to criticism?

• How do you handle disagreements with co-workers?

• Describe how you interact with Development Leads and Software Engineers

• Describe your leadership style.

• What challenges have you faced when working remotely? How have you overcome them?

• How do you approach team building when that team has never met in person?

Database Questions:

1. What experience do you have working with databases in a devops environment?

2. How do you ensure the reliability and performance of databases in a production environment?

3. What tools and technologies do you use for database monitoring and troubleshooting?

4. How do you handle database backups and disaster recovery planning?

5. Can you give an example of a particularly challenging database issue you have encountered and how you resolved it?

6. How do you stay current with the latest trends and developments in database technologies?

7. How do you handle database migrations and upgrades in a devops environment?

8. How do you implement security measures for databases in a devops environment?

Possible Answers:

1. I have several years of experience working with databases in a devops environment, specifically with MySQL and PostgreSQL. I have experience implementing and maintaining database infrastructure in both cloud and on-premises environments.

2. I ensure the reliability and performance of databases by implementing best practices for database design and management, such as indexing and partitioning. I also use monitoring and performance tuning tools to identify and address any issues that may arise. Additionally, I conduct regular load testing to ensure that the databases can handle the expected traffic.

3. For database monitoring and troubleshooting, I use tools such as Prometheus and Grafana for monitoring and alerting, as well as tools such as pgAdmin and MySQL Workbench for troubleshooting and performance tuning.

4. I handle database backups and disaster recovery planning by implementing regular automated backups and testing restore procedures to ensure that they are functioning correctly. Additionally, I use replication and clustering to ensure high availability of the databases.

5. One particularly challenging issue I encountered was a database performance issue caused by a poorly designed schema. I resolved the issue by re-designing the schema to improve indexing and partitioning, as well as implementing caching and other performance optimizations.

6. I stay current with the latest trends and developments in database technologies by attending conferences, reading industry publications, and participating in online communities.

7. I handle database migrations and upgrades by thoroughly testing and planning the migration or upgrade, and then implementing it in a controlled and monitored manner to minimize any disruption to the service.

8. I implement security measures for databases by using encryption for sensitive data, implementing access controls and firewalls, and regularly patching and updating the database software.

AWS Q&A

Questions

1. Can you explain the concept of infrastructure as code and how it applies to AWS?

2. How do you handle scaling in AWS? Can you give an example of a time when you had to scale an application?

3. How do you ensure security and compliance in an AWS environment?

4. Can you explain the differences between Amazon EC2, Amazon ECS, and Amazon EKS?

5. How do you monitor and troubleshoot issues in an AWS environment?

6. Can you explain the concept of AWS Auto Scaling and how it works?

7. How do you manage and automate deployments in AWS?

8. Can you explain the concept of AWS IAM and how it is used to manage access and permissions?

9. How do you manage and optimize AWS costs?

Possible Answers:

1. Infrastructure as code refers to the process of managing and provisioning infrastructure using code, rather than manual processes. In AWS, this can be achieved using tools such as AWS CloudFormation or Terraform, which allow for the creation and management of infrastructure resources through code templates.

2. Scaling in AWS can be achieved through a variety of methods, such as using Auto Scaling groups to automatically add or remove instances based on demand, or manually adding or removing instances as needed. An example of a time when I had to scale an application was when we experienced a sudden spike in traffic to our website.

3. To ensure security and compliance in an AWS environment, I use a combination of AWS security services such as IAM for managing access and permissions, and VPC for creating secure networks. I also implement best practices such as encryption for sensitive data, and regular security audits and assessments.

4. Amazon EC2 is a service that allows for the creation and management of virtual servers, or instances. Amazon ECS is a service for running and scaling containerized applications, and Amazon EKS is a service for running and scaling Kubernetes clusters.

5. To monitor and troubleshoot issues in an AWS environment, I use tools such as CloudWatch for monitoring performance and logs, and CloudTrail for tracking API calls. I also use the AWS Trusted Advisor service for identifying potential issues and recommendations for optimization.

6. AWS Auto Scaling is a service that automatically scales instances based on predefined rules and policies. This can include scaling based on demand, such as increasing instances during peak traffic times and decreasing instances during off-peak times.

7. I use a variety of methods for managing and automating deployments in AWS, such as using CodePipeline and CodeDeploy for continuous integration and deployment, and using CloudFormation or Terraform for infrastructure as code.

8. AWS IAM (Identity and Access Management) is a service that allows for the management of users, groups, and permissions in an AWS environment. This can include creating and managing roles and policies for granting or denying access to specific resources.

9. To manage and optimize AWS costs, I use tools such as the AWS Cost Explorer for identifying and tracking costs, and the AWS Budgets service for setting and monitoring budget thresholds. I also use the AWS Reserved Instances service for reserving instances at a lower cost and the AWS Savings Plans for reducing costs on a long-term basis.

Terraform Q&A

Questions

1. How do you manage state files when using Terraform in a team environment?

2. Can you walk us through a recent project you worked on where you utilized Terraform for infrastructure as code?

3. How do you handle Terraform version and module version conflicts?

4. Can you explain how you use Terraform to provision and manage resources on AWS?

5. How do you handle sensitive data, such as access keys, when using Terraform?

6. Can you give an example of how you have used Terraform to automate scaling and load balancing for a web application?

7. How do you test Terraform code before deploying it to a live environment?

8. Can you explain how you use Terraform to manage and track changes to infrastructure over time?

9. How do you troubleshoot issues that arise when using Terraform?

Possible Answers

1. When using Terraform in a team environment, I use remote state management and version control systems such as Git to ensure that state files are kept in sync and can be easily audited.

2. In my most recent project, I used Terraform to provision and manage a multi-tier web application on AWS. I used Terraform to create and configure VPCs, subnets, security groups, and EC2 instances. I also used it to set up autoscaling and load balancing for the application.

3. To handle Terraform version and module version conflicts, I use a tool called Terragrunt which allows me to specify a specific version of Terraform to use and also allows me to specify the version of each module I use.

4. I use Terraform to provision and manage various resources on AWS such as VPCs, subnets, security groups, EC2 instances, RDS instances, S3 buckets, and more. I also use it to set up and configure services such as Elasticsearch, Kinesis, and SQS.

5. To handle sensitive data such as access keys when using Terraform, I use Terraform's built-in support for environment variables and also use external tools such as Hashicorp Vault.

6. One example of how I have used Terraform to automate scaling and load balancing is by using Terraform to create an autoscaling group and also to configure a target group and listener for an application load balancer. I then used Terraform to ensure that the desired number of instances were always running and the load was distributed evenly.

7. Before deploying Terraform code to a live environment, I use tools such as Terraform's built-in plan command and also use external tools such as Terratest to test my code.

8. I use Terraform's built-in state management and also use tools such as Terraform Enterprise to track changes to infrastructure over time. I also use Git to track changes to my Terraform code.

9. To troubleshoot issues that arise when using Terraform, I first check the Terraform state and then check the logs of the affected resources. I also refer to the Terraform documentation and troubleshooting guides, and if needed, I reach out to the Terraform community for help.

Scenarios

Question: As a devops engineer, what services would you recommend using in order to implement a reliable and performant real-time chat service on AWS using GitHub Actions for CI/CD and multiple environments?"

Sample Answer: "In order to implement a reliable and performant real-time chat service on AWS using GitHub Actions for CI/CD and multiple environments, I would recommend using the following services:

1. Amazon Elastic Container Service (ECS) or Kubernetes for container orchestration and management

2. Amazon Elasticache for caching and real-time data storage

3. Amazon Elastic Load Balancer (ELB) for load balancing and availability

4. Amazon CloudWatch for monitoring and logging

5. Amazon SNS for push notifications

6. Amazon RDS for persistent data storage

7. GitHub Actions for CI/CD pipeline and multiple environment management

8. Amazon CloudFront for CDN for faster delivery of media and other static assets.

Additionally, I would recommend implementing security best practices such as using Amazon VPC for network isolation, and Amazon IAM for access control and authentication. In order to ensure high availability and scalability, I would also recommend using Auto Scaling groups and multi-AZ deployments."


Question: You are a DevOps Engineer at a company that operates a large e-commerce platform. The platform is built on a microservices architecture and is hosted on a cluster of servers in a cloud environment. Recently, the company has experienced a significant increase in traffic, resulting in high levels of server utilization and slow response times for customers.

Your manager has tasked you with finding a solution to this problem. They have given you the following requirements:

• The solution must be able to handle the increased traffic without causing any downtime or service interruptions.

• The solution must be able to scale automatically based on the current traffic levels.

• The solution must be cost-effective and not require a significant investment in new hardware.

• The solution must be easy to implement and maintain.

Sample Answer:

To address this problem, I would propose implementing a containerization solution using Docker and/or Kubernetes. By containerizing the microservices, we can easily scale them up or down based on the current traffic levels. Kubernetes can also automatically manage the scaling of the containers, ensuring that there are always enough resources available to handle the traffic.

To ensure that there are no downtime or service interruptions, we can implement a rolling deployment strategy. This will allow us to update the containers without any service interruptions, as the new containers will be deployed alongside the old ones and gradually replace them.

In terms of cost-effectiveness, containerization and Kubernetes can be run on existing hardware, so there is no need for a significant investment in new hardware. Additionally, the use of containers allows for more efficient resource utilization, which can help to reduce costs.

Overall, I believe that this solution is a good fit for the company's requirements. It is able to handle the increased traffic, scale automatically, is cost-effective, and is easy to implement and maintain.