System Design Interview
guides and free resources

When you’re asked to design a hotel booking system in a system design interview, it’s not just about building a travel website. It’s about demonstrating your ability to design a...

If you’ve ever ordered something from Amazon and picked it up from a bright yellow locker instead of your front porch, you’ve already used one of the most fascinating real-world...

In the digital world, every click on an online ad tells a story—a user action that powers billion-dollar marketing systems. Companies like Google, Meta, and Amazon rely on ad click...

If you’ve ever used Redis, DynamoDB, or Memcached, you’ve already interacted with one of the most fundamental building blocks of scalable systems: the key-value store. These databases are everywhere: powering...

Every time you log in to your Google account and type in a 6-digit code from your phone, you’re relying on one of the most secure, widely used systems in...

When an interviewer asks you to design a search engine interview question for your System Design interview, it’s not because they expect you to replicate Google or Bing in 45...