⚡ New — notes, flashcards & SD challenges
Learn system design.
Actually understand it.
Actually understand it.
Structured concepts with diagrams, practice MCQs, and end-to-end system design challenges — all in one place. Take notes as you go.
✓ No card required⚡ Early access
Overview
Learn
Practice tests
SD challenges
Concepts
🗄 CachingFree
⚖ Load bal.Free
📚 DatabasesPro
📨 Msg queuesPro
SD challenges
🔗 URL shortener
🐦 Design Twitter
🗄 CachingFree
Caching stores frequently accessed data in fast storage so future requests skip the slow source — cutting latency and reducing DB load at scale.
Cache-aside read flow
📝 Notes — Caching
Today, 10:42 am
Write-around avoids polluting cache with cold data.
Yesterday
Cache stampede → mutex lock or PER.
Add a note...
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94
System design concepts
51
SD challenges
3
Difficulty levels
Everything you need
Learn, practice, design — in one flow
Not just content. A structured path from understanding a concept to designing a real system that uses it.
🗄
Concept learning with diagrams
Each concept has clear explanations and inline architecture diagrams — not walls of text.
📝
Notes, highlights & flashcards
Add notes as you read. Auto-highlights key insights. Flip flashcards to drill concepts later.
✅
Topic practice tests
MCQs per concept with explanations. Verify you've really understood before moving on.
🗺
End-to-end SD challenges
Design Twitter, YouTube, URL shorteners. Each challenge shows which concepts it tests.
⟳
Concept → design bridge
After each concept, a direct link to the SD challenge that uses it — cementing understanding.
📊
Progress tracking
See what you've completed, practice scores, and which concepts need more work.
How it works
Four steps to system design fluency
1
Pick a concept
Choose from caching, load balancing, databases, queues and more. Two free to start.
2
Learn with diagrams
Read structured content, study architecture diagrams, and save notes as you go.
3
Take the practice test
MCQs verify your understanding concept by concept — with explanations for every answer.
4
Attempt the SD challenge
Design a real system using what you've learned and see how multiple concepts combine.
Curriculum
94 concepts, 51 SD challenges
Two free concepts to start. Upgrade to unlock the full curriculum.
🗄
Caching
Cache strategies, Redis, CDNs, eviction policies, stampede prevention.
⚖
Load balancing
L4 vs L7, round-robin, least connections, health checks, sticky sessions.
💾
Databases & storage
SQL vs NoSQL, sharding, replication, indexing, ACID.
🔒 Pro
📨
Message queues
Kafka, pub/sub, fan-out, dead-letter queues, backpressure.
🔒 Pro
⬡
Consistent hashing
Distribute data across nodes with minimal reshuffling on changes.
🔒 Pro
🔒
+ 89 more concepts
Rate limiting, auth, real-time, streaming, payments, frontend architecture, and more.
🔒 Pro
Pricing
Start free. Upgrade when ready.
No credit card required to get started.
Free
₹0forever
✓2 free concepts (Caching, Load balancing)
✓Practice tests for free concepts
✓1 SD challenge (URL shortener)
✓Notes & flashcards
✓Advanced patterns & interview tips
✓Full SD challenge library
Pro
₹499/ month
✓All 94 concepts + advanced patterns
✓Full prompt library — all 51 challenges across 3 tracks
✓All 3 difficulty levels: beginner → senior
✓Diagram canvas with save & restore
✓Rule-based automated validation
✓Expert solutions for every prompt
✓Rubric scoring across 7 dimensions
✓AI-powered evaluation with score + feedback
✓Notes, highlights & flashcards
✓Interview tips per concept
✓Progress tracking & weak area detection
✓Next prompt recommendations
FAQ
Common questions
Yes. Caching and load balancing are among the most commonly tested system design concepts. You also get the URL shortener SD challenge, practice tests, and full notes/flashcard functionality.
Ready to get started?
94 concepts, 51 SD challenges. Free to start, no card required.