System Design 101

How to scale a website to 1 million users:

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• Prelaunch:

↳ Use a static web framework to save costs

• 10 Users: 

↳ Use a single virtual machine to run the entire website for simplicity

• 100 Users:

↳ Use separate virtual machines to run the backend and database to prepare for scale

• 1K Users:

↳ Setup more availability zones for resilience

↳ Use serverless to handle infrequent workloads

↳ Run a monolith architecture to keep things simple

↳ Use leader-follower database replication to scale reads

• 10K Users:

↳ Install autoscaling to scale quickly

↳ Replicate stateless web server for scale

↳ Cache popular reads to reduce infrastructure load

↳ Use load balancer to route traffic and increase performance

↳ Put static content, such as images and videos, in CDN for scale and low latency

↳ Setup a 3-tier architecture on separate virtual machines for scale and maintainability

• 100K Users:

↳ Use microservices for scale

↳ Add more availability zones for reliability and scale

↳ Add cache between the backend and database to reduce server load

↳ Introduce containers and kubernetes to reduce operational complexity

• 1M Users:

↳ Federate and partition database for scale

↳ Deploy servers across more regions for scale

↳ Setup a global load balancer to route traffic across regions for scale

The bottom line:

There are many ways to scale a website to 1 million users and this is simply one of them.

The best solution and the numbers depend on your needs.

Remember, everything is a tradeoff.

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What's your approach for scaling a website to 1 million users?