devops-interview-handbook

Junior DevOps Engineer Checklist

Use this checklist to assess your readiness for junior DevOps positions (0-2 years experience).

Linux Fundamentals

Basic Commands

• Navigate filesystem (cd, ls, pwd)
• File operations (cp, mv, rm, mkdir)
• Text processing (cat, grep, sed, awk)
• File permissions (chmod, chown)
• Process management (ps, top, kill)
• System information (df, du, free, uptime)

System Administration

• Understand file system structure (/etc, /var, /usr, etc.)
• Manage services (systemd: start, stop, enable, disable)
• Configure network interfaces
• Understand package management (apt/yum)
• Basic shell scripting (bash)
• Cron jobs and scheduling

Troubleshooting

• Check system logs (/var/log)
• Monitor system resources
• Debug process issues
• Check disk space and memory
• Basic network troubleshooting (ping, netstat, ss)

Cloud Basics (AWS)

Core Services

• EC2: Launch instances, security groups
• S3: Create buckets, upload/download files
• VPC: Understand subnets, internet gateway
• IAM: Users, roles, policies basics
• CloudWatch: View logs and metrics

Basic Operations

• Launch EC2 instance via console
• Create S3 bucket and upload files
• Configure security groups
• Understand regions and availability zones
• Basic IAM user/role creation

Containerization

Docker Fundamentals

• Understand containers vs VMs
• Docker commands (run, build, push, pull)
• Write basic Dockerfile
• Docker Compose basics
• Container networking basics
• Docker volumes

Hands-on

• Containerize a simple application
• Build and push image to registry
• Use Docker Compose for multi-container app
• Debug container issues

Version Control

Git Basics

• Clone, add, commit, push
• Create and merge branches
• Resolve merge conflicts
• Understand .gitignore
• Basic Git workflow

Collaboration

• Create pull/merge requests
• Code review basics
• Understand Git branching strategies

CI/CD Basics

Concepts

• Understand CI/CD pipeline
• Difference between CI and CD
• Basic pipeline stages (build, test, deploy)

Tools (Choose One)

• GitHub Actions: Basic workflow
• GitLab CI: Basic .gitlab-ci.yml
• Jenkins: Basic pipeline

Hands-on

• Create simple CI pipeline (build + test)
• Deploy to staging environment
• Understand pipeline logs and debugging

Infrastructure as Code Basics

Terraform Fundamentals

• Understand IaC concepts
• Basic Terraform syntax (resources, variables)
• Terraform commands (init, plan, apply)
• Understand state file

Hands-on

• Create simple infrastructure (EC2, S3)
• Use variables and outputs
• Understand terraform plan output

Monitoring & Logging Basics

Concepts

• Understand monitoring importance
• Basic metrics (CPU, memory, disk)
• Log aggregation basics
• Alerting concepts

Tools (Basic Familiarity)

• CloudWatch (AWS) or equivalent
• Basic log viewing
• Understand dashboards

Security Basics

Concepts

• Principle of least privilege
• Secrets management basics
• Encryption at rest and in transit
• Basic firewall concepts

Practices

• Never commit secrets
• Use strong passwords/keys
• Understand security groups/firewalls
• Basic SSL/TLS understanding

Networking Basics

Concepts

• Understand IP addresses and subnets
• Basic DNS understanding
• Ports and protocols (HTTP, HTTPS, SSH)
• Load balancing basics

Cloud Networking

• VPC basics
• Subnets (public vs private)
• Security groups
• Internet gateway basics

Scripting

Bash Scripting

• Write basic scripts
• Variables and conditionals
• Loops
• Functions basics
• Error handling basics

Python Scripting (Optional but Recommended)

• Basic Python syntax
• Work with APIs (boto3 for AWS)
• File operations
• Error handling

Problem-Solving Skills

• Can debug basic issues
• Read and understand error messages
• Use documentation effectively
• Ask for help when stuck
• Document solutions

Communication

• Can explain technical concepts clearly
• Write clear documentation
• Participate in team discussions
• Ask clarifying questions

Projects to Build

Beginner Projects

• Deploy static website to S3 + CloudFront
• Containerize a web application
• Set up basic CI/CD pipeline
• Create infrastructure with Terraform
• Set up monitoring and alerts

Portfolio

• GitHub profile with projects
• README files explaining projects
• Can discuss projects in interviews

Interview Readiness

Technical Questions

• Can explain Linux commands and concepts
• Can explain cloud services (EC2, S3, etc.)
• Can explain Docker and containers
• Can explain CI/CD pipeline
• Can explain basic troubleshooting steps

Behavioral Questions

• Can discuss learning experiences
• Can discuss problem-solving approach
• Can discuss teamwork
• Can discuss projects you’ve built

Hands-on

• Comfortable with command line
• Can write basic scripts
• Can deploy applications
• Can debug common issues

Study Resources

Recommended

• Linux Command Line book (free online)
• AWS Free Tier account
• Docker official documentation
• Terraform Learn (free)
• GitHub Actions/GitLab CI docs

Practice

• Set up home lab (VM or cloud)
• Complete hands-on tutorials
• Build personal projects
• Practice on real infrastructure

Assessment

If You Can Check 70%+:

✅ You’re ready for junior DevOps interviews!

Focus Areas if Below 70%:

1. Linux: Essential foundation, prioritize this
2. Cloud Basics: Get hands-on with AWS free tier
3. Docker: Containerize at least one application
4. CI/CD: Set up at least one pipeline
5. Practice: Build projects, don’t just read

Next Steps

1. Fill Gaps: Focus on areas with unchecked items
2. Build Projects: Create 2-3 complete projects
3. Practice: Use this handbook’s questions
4. Apply: Start applying to positions
5. Interview: Practice explaining concepts
6. Learn: Continue learning on the job

Tips for Junior DevOps Engineers

1. Hands-on Practice: More valuable than reading
2. Build Projects: Show what you can do
3. Ask Questions: Don’t be afraid to ask
4. Document Learning: Take notes, write blog posts
5. Join Communities: Learn from others
6. Be Patient: Learning takes time
7. Focus on Fundamentals: Strong foundation is key

Good luck! 🚀

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