AWS is a cloud computing platform that offers users a wide range of services, including storage, computing, and networking. It is one of the most popular cloud platforms on the market, and its popularity is only increasing as more businesses move to the cloud.
AWS is becoming a major focus of DevOps engineer jobs worldwide, and EPAM Anywhere is no exception to that trend. For anyone looking to prepare for AWS DevOps interview questions, we offer 20 essential questions and answers provided by EPAM Anywhere’s Certified DevOps Technical Interviewer, Systems Engineering Team Leader, Santiago Castellanos.
AWS DevOps interview questions: fundamentals
1. What are the top reasons for using AWS for DevOps?
When asked this question, I always like to name the main reasons promoted by AWS itself. Many of these reasons are consistent with DevOps culture and its underlying principles:
- Get started fast: each AWS service is ready to be used without any previous configuration.
- Fully managed services: this allows you to be focused solely on your product, rather than on making previous configurations work with your product.
- Built for scale: this has become really fundamental with today's technologies.
- Programmable: this allows us to automate and replicate our processes.
- Automation: this provides us with services focused especially on reducing process times.
All of this allows the DevOps culture to be fully adapted to a cloud provider like AWS, while also enabling companies to build products faster and more reliably by hiring DevOps engineers skilled in this provider's services.
2. Name the key components of AWS applied in DevOps
Each of the AWS services are designed to work based on the DevOps culture. But I think that the most important to highlight are those that allow a robust CI/CD system to exist, including: AWS CodePipeline, AWS CodeBuild, AWS CodeDeploy, and AWS CodeStar.
3. What is AWS CodePipeline?
AWS CodePipeline is a fully managed CI/CD service that enables you to automate release pipelines for fast and reliable application and infrastructure updates.
4. Which languages and frameworks are compatible with AWS CodeBuild?
AWS CodeBuild provides preconfigured environments for supported versions of Java, Ruby, Python, Go, Node.js, Android, .NET Core, PHP, and Docker. You can create and upload a Docker image to the Amazon EC2 Container Registry or the Docker hub registry to customize your environment, and later reference this custom image in your build project.
5. Describe a use case for Amazon Elastic Container Service (ECS) in DevOps
The most common case is when you have a microservice that you want to deploy in an environment without any prior provisioning. You can achieve this by creating a Docker image of the microservice and saving it in an image registry, such as the Elastic Container Registry (ECR) which can later be used in a Task Definition. Using technologies such as Fargate, you can then deploy this in an ECS cluster.
6. What is AMI?
An Amazon Machine Image (AMI) is an image supported and maintained by AWS that delivers the information needed to launch an instance.
7. Describe Infrastructure as Code (IaC) in your own words.
IaC is the management of the infrastructure (networks, virtual machines, load balancers, and connection topology) in a descriptive model, using the same version control that the DevOps team uses for source code. This makes it replicable and consistent.
8. How do containers communicate in Kubernetes?
There are three ways containers can communicate with each other:
- Through the localhost and the port number exposed by the other container.
- Through a pod’s IP address.
- Through a service that has an IP address and usually also has a DNS name.
9. What’s your preferred version control system?
Personally, I prefer Git, but it’s fine if yours is different. Just be sure to follow up by mentioning the key reasons and advantages of your choice.
10. How is DevOps different from agile?
The goal of DevOps is to improve communication and collaboration between large teams who are responsible for developing software. This approach differs from that used in Agile, where small collaborating groups work together on adapting quickly as changes occur during the development process.
One key difference lies within how each side approaches a task. While Agile focuses mostly on getting things done, the main concern of DevOps includes communicating and connecting so people can learn from each other.
AWS DevOps interview questions and answers for experienced engineers
1. Can you define the DevOps lifecycle?
We can define the DevOps life cycle in eight simple words:
2. What’s the difference between AWS CloudFormation and AWS Elastic Beanstalk?
CloudFormation is mainly an infrastructure-as-code (IaC) service that allows you to easily model, provision, and manage AWS resources. Beanstalk, on the other hand, is more focused on application deployment; helping users avoid all the configuration issues that result from interacting with each service individually.
3. Name a few cloud security best practices
One best practice is that application security must be fully automated to keep pace with dynamic clouds and rapid software development practices. Another is that application security must be comprehensive in scope. A third best practice is that application security must provide accurate and insightful information, not just partial data.
4. How to implement IaC using AWS?
There are several ways, but the best option when dealing with AWS would be to make use of the CloudFormation service, which is dedicated to writing infrastructure as code. There are also other options that are pretty good and worth considering if we have multi-model clouds, such as Terraform or Pulumi. I prefer the use of Terraform over CloudFormation.
5. What is the main difference between Terraform and CloudFormation?
Terraform is a tool from Hashicorp, and CloudFormation is from AWS. When comparing the two, it’s important to realize that, unlike Terraform, CloudFormation is not open source and it follows a roadmap of features set by Amazon. Terraform is cloud-agnostic. It provides users with quite a bit of flexibility and Terraform can be used for any type of resource that can be interacted with via API.
6. What configuration management tools are compatible with AWS?
It is possible to use all configuration management technologies with AWS, but the only ones that have dedicated services are Chef and Puppet, which come bundled with AWS OpsWork.
7. Explain how you solved a challenge related to creating a DevOps pipeline
It is important to gather all of the requirements for the pipeline that is going to be created. Talk with the development teams in the case of an application or, in other cases, with the team that requires the functionality, to define how the pipeline is going to be divided and which tools are needed to make it work. Initially, it is important to try to replicate as much of the pipeline as possible locally, so that later you can automate the process. Finally do several tests to ensure that the workflow concept will actually work.
8. Why is buffer important in AWS?
Buffer helps to synchronize different components, it receives requests and processes them asynchronously. It manages the balance between various components to maintain speed and provide faster service. In AWS, buffering also ensures efficiency over traffic or load.
9. Why can ECS be a better choice than Kubernetes?
If you want an implementation with a lot of flexibility, greater scalability, and simplicity, it is better to use ECS.
10. What’s the impact of microservices on operations?
Mainly that the operational load is reduced considerably due to the simplicity behind the microservices and the ease of replacing them in a matter of minutes.
Extra tips for passing an AWS DevOps interview
There are several things that I consider really important at the time of an interview:
- Be honest with each of your answers. It is not necessary to know everything. Sometimes, it is okay to say you don’t know, but at the same time it is important to demonstrate logical reasoning and problem-solving skills. So, if you don’t know the answer, make assumptions based on your knowledge of other areas or previous experiences. Your response could be something like: "I don't know the answer, but I've heard that it works very similarly to... therefore, I think it could be used in the following way..." This way the interviewer can get an idea of how you think and how you can solve problems.
- DevOps is a discipline that requires a lot of flexibility, adaptability, and creativity. It is necessary to continue learning at all times and practice exercises with complex problems that may arise on a day-to-day basis.
- As an interviewee, it is also essential to practice your interview skills so that you can better handle your nerves and deal with any tension you might experience.
- Last but not least, always be well-informed about the latest trends. The DevOps culture is growing at a very fast pace and many new tools are released every day that you should be familiar with.
If you’re looking for a career in DevOps, check out open jobs at EPAM Anywhere. We can help you take the next step in your career.