System Designer

Real-world Case Studies

Learn from the world's most successful tech companies. Dive deep into their architectures, challenges, and the engineering decisions that power billions of users.

10
In-depth Studies
NaNB+
Combined Users
Real
Production Systems

System Design

Advanced

Key-Value Store (DynamoDB-style)

Design a distributed key-value store with consistent hashing, replication, and tunable consistency

SCALE
Billions of KV pairs
10M QPS
CHALLENGE
Distributed consensus, partitioning, fault tolerance
INFRASTRUCTURE
Distributed hash ring
Consistent HashingVector ClocksQuorumMerkle Trees
30 min

System Design

Intermediate

Unique ID Generator (Snowflake)

Build a distributed unique ID generator like Twitter Snowflake for massive scale

SCALE
1000+ servers
10K IDs/sec per server
CHALLENGE
Global uniqueness, time ordering, high throughput
INFRASTRUCTURE
Stateless generation
Snowflake AlgorithmClock SyncBit ManipulationDistributed Systems
25 min

System Design

Advanced

Web Crawler (Googlebot-style)

Design a scalable web crawler for search engines with politeness and duplicate detection

SCALE
1B pages/month
400 pages/sec
CHALLENGE
Politeness, duplicate detection, crawler traps
INFRASTRUCTURE
Distributed crawling
URL FrontierBloom FiltersRobots.txtContent Processing
35 min

Netflix

Advanced

Global Video Streaming at Scale

How Netflix serves 230M+ subscribers with 15,000+ titles across 190+ countries

SCALE
230M users
1B+ hours/month
CHALLENGE
Massive global scale, content delivery, personalization
INFRASTRUCTURE
700+ microservices
MicroservicesAWSCDNMachine Learning
25 min

WhatsApp

Advanced

Messaging 2 Billion Users with 55 Engineers

The engineering philosophy and architecture behind WhatsApp's incredible efficiency

SCALE
2B users
100B messages/day
CHALLENGE
Extreme efficiency, real-time messaging, minimal team
INFRASTRUCTURE
55 engineers
ErlangFreeBSDMnesiaXMPP
20 min

Uber

Advanced

Real-time Matching & Geospatial Systems

Connecting millions of riders and drivers in real-time across global cities

SCALE
100M+ users
15M trips/day
CHALLENGE
Real-time matching, geospatial queries, surge pricing
INFRASTRUCTURE
4000+ microservices
MicroservicesRedisS2 GeometryApache Kafka
22 min

Discord

Intermediate

Real-time Communication Platform

Building a platform for 150M+ users with voice, video, and text chat

SCALE
150M users
4B messages/day
CHALLENGE
Real-time communication, voice quality, gaming communities
INFRASTRUCTURE
Global edge network
ElixirRustWebRTCCassandra
18 min

Instagram

Intermediate

Photo Sharing & Social Network

From 13 employees to 1B+ users: Instagram's journey and architecture evolution

SCALE
1B+ users
500M+ photos/day
CHALLENGE
Photo storage, feed generation, rapid growth
INFRASTRUCTURE
Sharded PostgreSQL
DjangoPostgreSQLCassandraMemcached
20 min

Zoom

Intermediate

Video Conferencing at Pandemic Scale

How Zoom scaled from 10M to 300M daily users during COVID-19

SCALE
300M users
3B+ minutes/day
CHALLENGE
Video quality, sudden 30x growth, reliability
INFRASTRUCTURE
Global data centers
Custom Video CodecsUDPWebRTCAuto-scaling
15 min

GitHub

Advanced

Software Collaboration Platform

Building the world's largest software development platform with Git hosting, CI/CD, and AI tools

SCALE
100M+ users
330M+ repositories
CHALLENGE
Git infrastructure, collaboration tools, massive scale
INFRASTRUCTURE
Microservices architecture
Ruby on RailsGitKubernetesElasticsearch
25 min

Study Methodology

Each case study includes architecture diagrams, scaling challenges, key design decisions, lessons learned, and actionable takeaways you can apply to your own systems.

Deep Dive:

Technical architecture and implementation details

Real Numbers:

Actual performance metrics and scale data

Lessons:

Key takeaways and design principles