DevOps Interview: A Guide for All Levels

Let's Do a Comparison of Junior, Mid-Level, and Senior DevOps interviews

A Comprehensive Guide for Junior, Mid-Level, and Senior Candidates

The DevOps job interviews can seem scary, especially when you're dealing with different expectations based on how experienced you are.

I've noticed that most companies follow similar steps in their interviews, regardless of whether you're applying for a Junior, Mid-Level, or Senior role. This blog series is all about making these interviews less confusing.

I've had about 12 interviews so far, and I want to share what I've learned to help you do well in your next interview, no matter where you're at in your career.

Understanding the DevOps Interview

Before we get into the details, let's talk about the big picture of a DevOps interview. While every company does things a bit differently, I've noticed there are mainly Two types of interviews that most companies use.

Type 1: HR Screening --> Technical Questions --> Offer
Type 2: HR Screening --> Technical Questions --> Technical Task --> Offer

Some companies prioritize traditional question-and-answer formats, while others favor practical technical tasks. Personally, I find technical tasks to be a better gauge of a candidate's abilities, allowing them to showcase their skills in a real-world setting.

Essential Technologies for DevOps

While specific technologies may vary between companies, several tools and concepts consistently appear in DevOps job descriptions. Familiarity with these technologies will give you a solid foundation:

Infrastructure Tools:
Terraform
Ansible
AWS
Azure

Containerization:
Kubernetes
Docker
Packer
ArgoCD (often paired with NGINX Ingress Controller, Cert Manager, Grafana, Prometheus, Loki, Thanos)

Code (not always required):
Python
Java

While not an exhaustive list, these technologies represent a significant portion of the current DevOps landscape. Aim to be familiar with at least 70% of these to increase your chances of landing a DevOps role.

Technical Questions

Common technical questions are asked by the following people:

HR: Expect general questions about your experience and knowledge.

Management/Team Leads: They delve deeper into your experience and expertise, but the questions remain relatively general.

Engineers: Be prepared for situation-based questions that often evolve into discussions. You may also face quick, technology-specific questions.

Architects: These individuals tend to ask more abstract theoretical questions, potentially exceeding the scope of the position you applied for. Be prepared for challenging, situation-based questions that test your problem-solving skills.

Tip: Don't try to overextend yourself. Focus on topics you genuinely understand and can discuss confidently. If faced with an unfamiliar topic, try to relate it back to your existing knowledge base to demonstrate your ability to think critically and make connections.

Tackling Technical Tasks

For many, technical tasks provide a welcome opportunity to showcase their practical skills.

• Some common technical task formats I've encountered:
• Individual task with a deadline of 3-7 days.
• Individual task with a time limit of 1-3 hours.
• Collaborative task completed within a 1-hour timeframe.

Remember, companies may revisit your completed tasks in subsequent interviews. Ensure you retain access to your resources (code, infrastructure, etc.) until the interview process concludes. If necessary, ask for permission before deleting anything.

Now Let's Start

Junior Level DevOps Interviews

Junior-level interviews are often viewed as both the easiest and most challenging to conquer. While the expectations are generally lower, it can be difficult to stand out without prior experience. Essential skills and expectations for Junior DevOps roles.

Skills Required

No Prior Experience:

• Create a compelling Github profile showcasing simple projects (e.g., a Bash script for WordPress deployment, Terraform examples, Dockerfile examples).
• Demonstrate foundational knowledge of key DevOps technologies (cloud platforms like AWS and Azure, CI/CD pipelines, Infrastructure as Code, Containers, Networking, and basic Linux commands).
• Craft a concise and visually appealing resume highlighting your transferable skills and enthusiasm for DevOps.
• Consider obtaining a relevant certification in a programming language or cloud platform (AWS Cloud Practitioner is a great starting point).

With Prior Experience (0-1 year as a System Administrator, SRE, Tech Support, or Developer):

• Cover the "no prior experience" points but focus your resume on your relevant work experience.
• Highlight projects you've undertaken outside of work to demonstrate your passion and initiative.

What to Expect in the Interview:

1. HR Screening: Introductions, CV review, scheduling of technical interviews.
2. Technical Interview: Expect questions covering your CV, along with technical inquiries exploring topics like:

• Cloud Platforms (AWS or Azure)
• Automation (Infrastructure as Code, Terraform, CI/CD)
• Networking (DNS, OSI Model, Subnetting)
• Linux (Basic commands, boot process, kernel, package managers, permissions, Bash)
• Containers and Virtualization (What is a container? Differences between VMs and containers? What is Kubernetes?)

Remember: At the Junior level, companies are looking for motivated individuals with a strong willingness to learn and exceed expectations. Use your Github profile to showcase your initiative and don't be afraid to engage in discussions even if you don't have a definitive answer. The ability to think critically and problem-solve is more valuable than memorizing specific facts.

Now Let's Move On To

Mid-Level DevOps Interviews

Moving up the ladder to Mid-Level roles, the expectations increase. The interview process typically follows the HR --> Technical Questions --> Technical Task --> Offer format, with a stronger emphasis on practical skills.

Interview Process:

1. Technical Questions: While the topics overlap with Junior-level interviews, the manner in which you answer becomes crucial. Confidence and a deeper understanding of the DevOps landscape are key.
2. Technical Tasks: The complexity and depth of the tasks increase, often mirroring the tasks given to Senior-level candidates

Technical Questions:

Expect in-depth conversations on topics like:
Cloud - AWS:
S3, EFS, EBS
ELB, NLB, ALB
RDS, Aurora, DynamoDB
ECS, EKS, Fargate, EC2
Cloudfront, Route53

Cloud - Azure:
Keyvault, Storage Account
VNET, Subnets, NAT, Route Table, Load Balancer, DNS Zones
Virtual Machine, AKS
Managed Databases, Azure Databases
Application Gateway
Automation:
Build Pipelines, Release Pipelines, Multi-stage pipelines
Dockerfiles, Multi-stage container builds
Terraform (init, plan, apply, workspaces, local vs remote state, AWS state lock)
Ansible Playbooks

Containerization:
Kubernetes (Deployments, Services, Ingresses, Secrets, Nodes, PVCs, Storage Classes, ConfigMaps, Policies)
Nginx Ingress Controller, Cert-Manager, External Secrets, External-DNS, Grafana, Prometheus
ArgoCD (Projects, Policies, Roles, Repositories, Clusters, app-of-apps)
Microservice vs Monolith

Linux:
Basic Commands
Troubleshooting & Investigation Skills

Technical Tasks:

• Be prepared to demonstrate your practical skills through tasks like:
• Creating a Dockerfile for an application (Python, JavaScript, .NET)
• Building and deploying a simple application on Kubernetes (Deployment, Service)
• Creating a pipeline that builds an application, pushes it to a container registry, and automatically updates image versions in a Git repository
• Installing and configuring Nginx Ingress Controller (Ingresses) and Cert-Manager (Certificates, Secrets)
• Creating an Ansible Playbook to install a LAMP stack on multiple hosts

Conclusion:
While Mid-Level DevOps interviews demand a broader range of expertise, remember, you're not expected to be a team leader or a cloud architect. Be honest about your experience and showcase your growth from your Junior days. Demonstrate your practical skills and highlight your accomplishments. Confidence and a genuine passion for DevOps will go a long way!

Now Finally Move To Last

Senior Level DevOps Interviews

Senior-level interviews represent the pinnacle of the DevOps career ladder. Companies seek individuals with deep technical expertise, strong leadership qualities, and the ability to mentor and guide teams.

Interview Process:

The interview process for senior roles typically involves multiple rounds, focusing on:

• Technical Expertise: In-depth discussions on complex architectural designs, troubleshooting intricate production issues, and optimizing CI/CD pipelines for performance and scalability.
• Leadership and Communication: Assessing your ability to lead teams, delegate effectively, communicate technical concepts clearly, and influence stakeholders.
• Problem-Solving and Decision Making: Evaluating your ability to analyze complex situations, develop innovative solutions, and make sound judgments in high-pressure environments.
• Cultural Fit and Values: Determining whether your values align with the company's culture and if you possess the interpersonal skills to foster a positive and collaborative team environment.

Technical Questions:

Be prepared to engage in intricate discussions on topics like:

• Advanced Cloud Architecture: Designing highly available and scalable cloud infrastructure using services like AWS EKS, Azure AKS, serverless computing, and managed database solutions.
• Security Best Practices: Implementing robust security measures for cloud environments, including identity and access management (IAM), network security groups, encryption, and compliance audits.
• Monitoring and Observability: Building comprehensive monitoring solutions using tools like Prometheus, Grafana, and ELK stack to gain insights into system performance, detect anomalies, and optimize resource utilization.
• Infrastructure as Code: Utilizing advanced Terraform and Ansible features to manage complex infrastructure deployments, automate infrastructure provisioning, and enforce configuration consistency across environments.
• CI/CD Best Practices: Architecting high-performance CI/CD pipelines, incorporating best practices for automation, testing, deployment strategies (blue-green, canary), and rollback procedures.

Technical Tasks:

While similar in nature to mid-level tasks, senior-level technical assessments will often include:

• Designing and Building a Complex Microservice Architecture: This could involve containerization, orchestration, service discovery, and deployment strategies.
• Troubleshooting a Realistic Production Issue: You might be presented with a simulated production outage and tasked with identifying the root cause, implementing a fix, and preventing future occurrences.
• Optimizing a CI/CD Pipeline for Performance and Scalability: This could involve implementing caching, parallel processing, and other optimization techniques.

Leadership and Communication Assessment:

Be prepared to discuss:

• Your experience leading and mentoring teams, fostering collaboration, and resolving conflicts.
• Strategies for communicating complex technical concepts to both technical and non-technical audiences.
• Your approach to problem-solving, decision making, and risk management.

Conclusion:

Senior-level DevOps interviews are demanding but also rewarding. They offer a chance to showcase your deep expertise, leadership capabilities, and ability to solve complex problems. Thorough preparation, confidence in your skills, and a passion for delivering exceptional results will set you apart as a top candidate.

This concludes our exploration of the DevOps interview landscape across Junior, Mid-Level, and Senior roles. Remember, practice is key, and building a solid foundation in the essential technologies discussed will greatly increase your chances of success

    **Best of luck in your DevOps journey**