10 Things You Can Learn from Netflix’s Architecture

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credit - ByteByteGo

Hello devs, ever since big tech companies have increased focus on System design, everyone has started learning the architecture of existing systems, which is good because there is no better way to learn than studying existing real-world, large-scale apps like Netflix.

Last month's Microsoft and Crowtstrike global outage which affected more than 9 million devices also shows how interconnected our world is now that an update can cause thousands of flight delays and trouble to millions of people.

Netflix, with its 247 million subscribers, showcases a remarkable system architecture that ensures seamless streaming and exceptional user experience, but how does it do it?

I spent quite a lot of time on that and I will share my learning in this article.

But if you are preparing for a System design interview then learning about distributed systems like Netflix is an important topic for System design interviews.

Apart from preparing common System design questions like API Gateway vs load balancer, Forward Proxy vs Reverse Proxy as well common System Design problem, it makes sense to learn about how big tech are solving system design problems.

Btw, if you are preparing for System design interviews and want to learn System Design in-depth then you can also check out sites like ByteByteGo, Design Guru, Exponent, Educative, Codemia.io and Udemy which have many great System design courses

Also, a solid knowledge of various Architecture patterns like Peer to Peer Patterns, and API Gateway goes a long way in designing systems that can withstand the test of time on production, on that note, here is a nice diagram from DesignGuru.io on Microservices architecture:

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How to learn about Netflix Architecture?

I started learning about Netflix architecture 3 weeks ago, my first stop was YouTube and I came across many Netflix architecture videos which I will share in this article also along with the lessons I learned.

The first video I watched was about how to design Netflix from Exponent, one of my favorite channels if you are preparing for a System Design Interview

I watched this video to understand the problem and my solution before I could see how Netflix solved these problems.

If you want to learn better from Netflix architecture you should watch this video first because it will stimulate your mind to solve those software design problems and you will most likely struggle with your limited knowledge but that's also like creating the ground for learning better.

The next video I watch is about the Evolution of Netflix API architecture video from BytBytGo, one of my favorite YouTube channel for System design.

This video showed how Netflix API architecture evolved starting from Monolith to Direct Access to Gateway Aggregation Layer and now Federated Gateway.

Well, many of these terms will sound foreign as they are very advanced techniques but in a nutshell, they just solve problems that come at scale. You should watch the video to understand them better.

And third video I watched is from InfoQ, another reputed YouTube channel for tech, which talks about the use of Microservices on Netflix

Another video that caught my attention about Netflix architecture was how Netflix servers millions of its customers across the globe

I also spend time reading Netflix TechBlog, which is also one of the great software engineering blogs you can read on System design

After spending this much time I got some idea of Netflix architecture and I learned a couple of lessons which I am going to share with you in this article.

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10 System Design Lessons from Netflix Architecture

Here are ten system design lessons gleaned from Netflix's architecture that can help you understand the intricacies of building scalable, reliable, and efficient systems.

1. Client-Backend-CDN Architecture

Netflix's architecture is divided into three primary components: the client, the backend, and content delivery network (CDN).

The client could be a mobile app, web browser, or smart TV app.

The backend runs on AWS, handling tasks like content personalization and payment processing.

The CDN, specifically Netflix's custom Open Connect Appliance (OCA), stores and streams videos.

Lesson: A clear separation of responsibilities across client, backend, and CDN components ensures efficient handling of tasks and scalability.

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2. Use AWS for Backend Scalability

Netflix runs its backend on AWS to leverage elasticity, allowing it to add servers during peak times and reduce them during off-peak times.

This pay-as-you-go model is cost-effective and flexible.

Lesson: Cloud services like AWS offer the scalability and flexibility needed to handle varying loads efficiently.

3. Use Microservices Architecture

Netflix operates around 700 microservices, utilizing databases like DynamoDB and Cassandra. This microservices architecture enables modularity, ease of maintenance, and independent scalability.

Lesson: Microservices architecture enhances scalability, fault isolation, and development agility.

Btw, if you are wondering what tech stack is used by Netflix, here is a nice diagram describing Netflix's tech stack from none other than ByteByteGo

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4. Use Geographical Redundancy for Reliability

Netflix runs its backend services across multiple availability zones and AWS regions, ensuring high availability and fault tolerance.

This is important to ensure that Netflix won't go down when one of the AWS data centers has a power outage or shut down due to a natural disaster.

Lesson: Geographical redundancy enhances system reliability and minimizes the impact of regional failures.

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5. Custom CDN: Open Connect Appliance (OCA)

Netflix's custom CDN, OCA, is built with commodity hardware optimized for delivering large files.

OCAs are installed at ISPs to keep them close to users, reducing latency and improving streaming quality.

Lesson: Custom CDNs tailored to specific needs can outperform general-purpose solutions, offering better control and efficiency.

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6. Intelligent Content Delivery

When a u*ser presses play, the Netflix client connects to the nearest OCA* based on network conditions, ensuring optimal streaming performance.

OCAs automatically switch if there's network congestion or failure.

Lesson: Intelligent content delivery mechanisms that adapt to network conditions enhance user experience and ensure reliability.

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7. Efficient Transcoding

Netflix supports 2200 different devices, each requiring specific video formats.

Videos are transcoded into various formats and split into chunks to support adaptive bitrate streaming, adjusting video quality based on network conditions.

Lesson: Efficient transcoding and adaptive bitrate streaming ensure high-quality playback across diverse devices and varying network conditions.

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8. Predictive Caching

Netflix predicts the videos users are likely to watch and caches them in OCAs during off-peak hours, reducing bandwidth usage and improving streaming speed.

Lesson: Predictive caching strategies can significantly reduce load times and bandwidth costs, enhancing user experience.

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9. Digital Rights Management (DRM)

Netflix adds DRM to video files to encrypt content and prevent piracy, ensuring secure delivery of premium content.

Lesson: Implementing DRM protects intellectual property and ensures compliance with content licensing agreements.

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10. Adaptive Network Handling

Netflix's backend provides URLs to the 10 best OCAs based on the user's IP address. The client tests the network connection quality and selects the best OCA for streaming.

Lesson: Adaptive network handling and intelligent server selection optimize streaming performance and resilience.

And here is a nice animated diagram by Muhammad Saddam which gives a high-level overview of Netflix architecture:

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Best System Design Interviews Resources

And, here are curated list of the best system design books, online courses, and practice websites which you can check to better prepare for System design interviews. Most of these courses also answer questions I have shared here.

1. DesignGuru's Grokking System Design Course: An interactive learning platform with hands-on exercises and real-world scenarios to strengthen your system design skills.

2. Codemia.io: This is another great platform to practice System design problems for interviews. It has more than 120+ System design problems, many of which are free and it also has a proper structure to solve them.

3. "System Design Interview" by Alex Xu: This book provides an in-depth exploration of system design concepts, strategies, and interview preparation tips.

4. "Designing Data-Intensive Applications" by Martin Kleppmann: A comprehensive guide that covers the principles and practices for designing scalable and reliable systems.

5. LeetCode System Design Tag: LeetCode is a popular platform for technical interview preparation. The System Design tag on LeetCode includes a variety of questions to practice.

6. "System Design Primer" on GitHub: A curated list of resources, including articles, books, and videos, to help you prepare for system design interviews.

7. Educative's System Design Course: An interactive learning platform with hands-on exercises and real-world scenarios to strengthen your system design skills.

8. High Scalability Blog: A blog that features articles and case studies on the architecture of high-traffic websites and scalable systems.

9. YouTube Channels: Check out channels like "Gaurav Sen" and "Tech Dummies" for insightful videos on system design concepts and interview preparation.

10. ByteByteGo: A live book and course by Alex Xu for System design interview preparation. It contains all the content of System Design Interview book volumes 1 and 2 and will be updated with volume 3 which is coming soon.

11. Exponent: A specialized site for interview prep especially for MAANG companies like Amazon and Google, They also have a great system design course and many other materials that can help you crack FAANG interviews.

image_credit - ByteByteGo

You should also combine theoretical knowledge with practical application by working on real-world projects and participating in mock interviews. Continuous practice and learning will undoubtedly enhance your proficiency in system design interviews.

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Conclusion

That's all about the System Design lessons you can learn from Netflix architecture. Netflix's architecture exemplifies how thoughtful system design can handle massive scale and deliver a seamless user experience.

By leveraging cloud services, microservices architecture, custom CDN solutions, and intelligent content delivery strategies, Netflix ensures high performance, reliability, and scalability.

These lessons from Netflix's architecture offer valuable insights for anyone looking to build and scale robust systems.

For further reading and more detailed information on Netflix's architecture, you can watch the YouTube video I have shared and also check out the references below. If you found this article useful, consider sharing it with someone interested in system design.

References:

• Netflix Open Connect
• Netflix Tech Blog
• Medium: How Netflix Works
• High Scalability: Netflix
• Ars Technica: Netflix Cache Server