Introduction:

1. What is DevOps?

• DevOps is a combination of two words Development (Dev) and Operations (Ops). It’s not a tool or a programming language, but a culture, mindset, and set of practices that bring developers and operations teams together to deliver software faster, reliably, and continuously.

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So Overall What they do :

• Developers write the code.

• Operations manage servers and deployment.

• DevOps bridges the gap between them so both can work collaboratively instead of separately.

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2. The Problem Before DevOps (Why DevOps Was Needed)

• Development Team: Focused on writing code quickly and adding new features.

• Operations Team: Focused on keeping servers stable and secure.

• Developers would say: “It works on my machine.”

• Operations would say: “But it’s breaking on the server.”

• There was no collaboration, lots of manual work, slow releases, and blame game.

3. How DevOps Solves These Problems

1. Collaboration – Developers, testers, and operations work together as one team.

2. Automation – From building to testing to deploying, everything is automated using tools.

3. Continuous Integration and Continuous Delivery (CI/CD) – New code changes are automatically tested and deployed quickly.

4. Monitoring and Feedback – Once deployed, everything is monitored in real-time. The team gets feedback and improves continuously.

DevOps vs Agile vs SDLC

Netflix — Real Example of SDLC, Agile, and DevOps

Software Development Life Cycle (SDLC) at Netflix :

1. Plan how the platform should work.

2. Design how it will look.

3. Build the streaming system.

4. Test it for bugs and speed.

5. Launch it for users.

6. Keep fixing and improving it.

Agile at Netflix

• One sprint → Add “Continue Watching” feature.

• Next sprint → Add “Download for Offline” feature.

• Next sprint → Improve recommendations.

DevOps at Netflix

• New code is automatically tested and deployed every day.

• If a server fails, the system automatically shifts traffic to other servers.

💡 Simple Summary

🧠 Easy Memory Trick

SDLC = How Netflix planned the whole platform

Agile = How they built new features quickly

DevOps = How they deliver updates automatically every day

4. The DevOps Lifecycle :

1. Plan – Discuss features, goals, and requirements.
• (Tools: Jira, Trello)

2. Code – Developers write code.
• (Tools: Git, GitHub, GitLab)

3. Build – Code is compiled and built automatically.
• (Tools: Maven, Gradle)

4. Test – Automated testing ensures everything works fine.
• (Tools: Selenium, JUnit)

5. Release – Code is packaged and ready for deployment.
• (Tools: Jenkins, GitHub Actions)

6. Deploy – Code is deployed automatically to production servers.
• (Tools: Docker, Kubernetes)

7. Operate & Monitor – Monitor servers and apps for performance and issues. After monitoring, feedback goes back to planning forming an infinite feedback loop.
• (Tools: Prometheus, Grafana)

5. Key Principles of DevOps :

• Automation Everywhere – Reduce manual effort and human error.

• Continuous Integration (CI) – Merge code frequently into a shared repository.

• Continuous Delivery (CD) – Automatically deploy tested code to production.

• Microservices Architecture – Break applications into smaller independent parts.

• Infrastructure as Code (IaC) – Manage servers and environments using code.

• Monitoring and Logging – Track performance and fix issues quickly.

• Collaboration and Communication – Teams work together transparently.

6. Where DevOps Fits in Modern Tech:

• Cloud platforms (AWS, Azure, GCP)

• Web and mobile app development

• Machine learning deployment (MLOps)

• Game development pipelines

• SaaS startups and large enterprises alike

7. Netflix: From 3 Days Outage to DevOps Powerhouse

Before DevOps (2008)

• Netflix hosted everything on its own data centers.

• As streaming users exploded, servers crashed frequently.

• Deployments were manual one wrong command = downtime.

• Dev & Ops teams worked separately, causing delays.

• In Aug 2008, a major database corruption shut Netflix down for 3 days.

• Millions of users couldn’t stream — huge revenue loss & trust damage.

The Shift (After 2008 Outage)

• Netflix moved completely to AWS Cloud.

• Adopted DevOps culture → collaboration + automation + monitoring.

• Introduced CI/CD pipelines (automatic testing & deployment).

• Built Chaos Monkey to test system resilience.

• Shifted to microservices → each part runs independently.

• Used tools like Grafana & Prometheus for real-time monitoring.

After DevOps (Results)

• Deployments: 1000+ per day.

• Uptime: 99.99% (almost no downtime)

• System scales automatically with traffic.

• Failures handled gracefully; no global outages.

• Netflix became a DevOps role model for tech companies.

💡 Takeaway

“Before DevOps, Netflix was breaking under pressure.

After DevOps, it learned to break things safely — and scale fearlessly.”