All coursesHow Senior Engineers Really Think About System Design & Architecture Part 1
Start with one server, break it on purpose, and fix each failure — building a production system from scratch.
Every concept is introduced by breaking the system first — so you understand why each piece exists, not just what it's called.
- Scaling: vertical (bigger machine) vs horizontal (more machines) and when to pick each
- Load balancers: what happens when requests need to be distributed — and the single point of failure you just created
- Stateless servers: why your login breaks across multiple servers and how to fix it with shared sessions (Redis)
- Connection pools: the hidden limit that crashes your database during traffic spikes
- Read replicas: offload reads, but accept that your app will be a little wrong on purpose
- Caching: trade correctness for speed — follower counts yes, bank balances never
- Queues & workers: stop making users wait for emails and notifications
- Sharding: the most powerful tool in the video — and the last one you should use
Developers who can build and deploy an app but want to understand what happens when it succeeds — when traffic spikes, databases hit their limits, and one server is no longer enough. Also great for anyone preparing for system design interviews. Curriculum
01System Design from Scratch Vertical vs horizontal scaling, load balancers, stateless sessions, connection pools, read replicas, caching, queues with workers, and sharding — each introduced only when the system breaks. FreeWhat's includedBuild a full architecture from a single server Understand the cost of every piece you add Real-world examples from digital banking