System Design track
You are the founding engineer at a startup on the brink of explosive growth. Every chapter is a crisis. Every solution is a lesson. Every decision shapes your architecture. This is not just learning — it is surviving the scale.
12
Chapters
0→∞
Scale journey
100%
Narrative driven
3
Difficulty levels
Difficulty:
BeginnerIntermediateAdvancedThe Scaling Saga — 12 Chapters
Chapter 01
BeginnerLaunch day. Your app is live. A single server, a simple database, and dreams of changing the world.
CRISIS
“The homepage is loading in 8 seconds. Users are bouncing. What do you do?”
👥 10 users
Start chapter →Chapter 02
BeginnerA celebrity tweeted about you. Traffic 100x overnight. Your single server is on fire. Literally.
CRISIS
“502 Bad Gateway. Everything's down. Angry users flooding Twitter. Fix it NOW.”
👥 10K users
Coming soonChapter 03
IntermediateYour PostgreSQL server is maxed out. Queries taking 10+ seconds. The database is the new bottleneck.
CRISIS
“Users can't load their profiles. Checkout is timing out. Revenue is bleeding.”
👥 100K users
Coming soonChapter 04
IntermediateUsers in Tokyo see different data than users in New York. Your global expansion broke everything.
CRISIS
“A user just bought the same item twice. Inventory says 0, but sales went through.”
👥 500K users
Coming soonChapter 05
IntermediateYour codebase is a tangled mess. One bug crashes everything. Deployments take hours. It's time to split.
CRISIS
“Payment service is down, taking the entire app with it. Users can't even browse.”
👥 1M users
Coming soonChapter 06
AdvancedEmail sends are blocking checkouts. Image processing crashes servers. Synchronous is killing you.
CRISIS
“Black Friday. Order confirmations delayed 2 hours. Customers think they weren't charged.”
👥 2M users
Coming soonChapter 07
AdvancedAWS had an outage. Your primary database corrupted. A developer pushed bad code to production. Chaos.
CRISIS
“The app is down. Customers are furious. Investors are calling. What's your disaster plan?”
👥 3M users
Coming soonChapter 08
AdvancedUsers want instant search. Autocomplete. Typo tolerance. Fuzzy matching. SQL can't handle this.
CRISIS
“Search is the #1 feature request. Competitors have it. You don't. Build it or lose users.”
👥 5M users
Coming soonChapter 09
AdvancedYour app needs live chat, notifications, collaborative editing. WebSockets? Long polling? What scales?
CRISIS
“Users demand real-time updates. Slack does it. Why can't you? Build it or they leave.”
👥 7M users
Coming soonChapter 10
AdvancedA hacker found an SQL injection. User data leaked. Regulatory fines incoming. Security isn't optional.
CRISIS
“TechCrunch just reported your data breach. Stock plummets. Trust shattered. Fix everything.”
👥 8M users
Coming soonChapter 11
AdvancedYou're sitting on petabytes of data. Analytics is slow. ML models need training. Build a data pipeline.
CRISIS
“Investors want metrics. Marketing wants insights. ML team is blocked. Build it yesterday.”
👥 9M users
Coming soonChapter 12
AdvancedYou've scaled to 10M users. Congratulations. Now prepare for 100M. The final boss: infinite scale.
CRISIS
“Design the architecture for 100M users. Every decision matters. This is your masterpiece.”
👥 10M users
Coming soonHow chapters work
Each chapter starts with a crisis. You read the situation, then learn the concepts that solve it.
Chapters will be published one by one. When a chapter is ready, the “Coming soon” badge becomes a clickable “Start chapter” link. The content order follows the scale arc — start from Chapter 01 and work forward.