System Design

Step-by-step design walkthroughs with real capacity estimates, component breakdowns, trade-off discussions, and interview tips. Learn the patterns that power systems at millions of users.

Design Studio

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Drag components onto a canvas, draw the flow, and get Aria's interviewer review — the skill that decides final rounds.

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14 cases

Design a URL Shortener

Build a system like bit.ly — billions of redirects, sub-20ms latency, globally available.

Beginner20 minStorage & Retrieval

Design a Chat System

Build real-time 1:1 and group messaging at WhatsApp scale — 50B messages per day.

Intermediate25 minReal-Time Systems

Design a Social Media Feed (Twitter/X)

Build a real-time feed for 300M daily users — fan-out at scale, celebrity problem, and sub-100ms timeline loads.

Intermediate28 minFeed & Messaging

Design a Video Streaming Platform (Netflix)

Stream to 220M subscribers at 15% of global internet traffic — transcoding pipelines, CDN at scale, and adaptive bitrate.

Advanced35 minStreaming & Media

Design an E-Commerce Platform (Amazon/Flipkart)

Handle 300M products, 100K orders/day peak, and flash sales — without overselling a single unit.

Intermediate30 minTransactions & Consistency

Design a Ride-Sharing App (Uber/Ola)

Build a global ride-sharing platform — 25M trips/day, 5M drivers online, sub-second driver matching.

Advanced30 minGeospatial & Real-Time

Design a Notification System

Build a multi-channel notification platform — 10M notifications/day across push, email, and SMS.

Beginner20 minMessaging & Queues

Design a Distributed Cache

Build a Redis Cluster — consistent hashing, sub-millisecond reads, cache stampede protection, and automatic failover.

Intermediate25 minStorage & Infrastructure

Design a Rate Limiter

Protect your API from abuse and overload — enforce per-user, per-IP, and global request quotas at millisecond latency.

Intermediate25 minAPI Infrastructure

Design a Video Streaming Platform

Build a YouTube-style platform — chunked uploads, multi-resolution transcoding, HLS delivery, and adaptive bitrate streaming at global CDN scale.

Advanced40 minStreaming & Media

Design Search Autocomplete

Build a typeahead system like Google Search — returning top-K suggestions in under 100ms for billions of daily queries.

Intermediate25 minSearch & Discovery

Design Dropbox / Google Drive

A file storage + sync service — upload once, see it instantly on every device, at petabyte scale.

Advanced25 minStorage & Retrieval

Design Ticketmaster / BookMyShow

An event ticketing system — browse events, hold a seat, pay, and confirm, without ever double-booking a seat.

Advanced25 minTransactions & Consistency

Design Instagram

A photo-sharing social network — upload media, follow people, and load a personalized home feed in milliseconds.

Intermediate25 minSocial & Feed

Want structured learning?

The System Design Mastery course covers CAP theorem, consistent hashing, caching strategies, Kafka, and complete designs for URL shorteners and notification systems - with video lessons and a certification exam.