Design Problems

Practice with 36 real-world system design problems

URL Shortener

MUST KNOW
Easy
hashingdatabasecachingscalability
Not Started

Twitter/News Feed

MUST KNOW
Hard
fan-outcachingtimelinepub-sub
Not Started

WhatsApp/Chat System

MUST KNOW
Hard
websocketmessagingencryptionpresence
Not Started

YouTube/Video Streaming

SHOULD KNOW
Hard
streamingcdntranscodingstorage
Not Started

Uber/Ride Sharing

SHOULD KNOW
Hard
geospatialreal-timematchinglocation
Not Started

Amazon E-commerce

DEEP DIVE
Hard
inventoryorderingpaymentsearch
Not Started

Notification System

MUST KNOW
Medium
push-notificationspub-subtemplatingpriority
Not Started

Rate Limiter

MUST KNOW
Medium
distributed-systemsredisalgorithmsthrottling
Not Started

Distributed Cache

SHOULD KNOW
Medium
cachingconsistent-hashingreplicationeviction
Not Started

Search Autocomplete

MUST KNOW
Medium
triecachingrankingreal-time
Not Started

Google Drive/Dropbox

SHOULD KNOW
Hard
file-syncchunkingdeduplicationconflict-resolution
Not Started

Payment System

SHOULD KNOW
Hard
consistencyidempotencysagareconciliation
Not Started

Ticketmaster

SHOULD KNOW
Hard
concurrencyinventoryqueuingflash-sale
Not Started

Web Crawler

DEEP DIVE
Medium
distributed-systemsqueuededuplicationpoliteness
Not Started

Instagram

SHOULD KNOW
Hard
feedmediasocial-graphstories
Not Started

Twitter Search / Full-Text Search Engine

DEEP DIVE
Medium
SearchElasticsearchIndexing
Not Started

Metrics/Monitoring System (like Datadog)

DEEP DIVE
Hard
Time-seriesAggregationAlerting
Not Started

Google Maps

DEEP DIVE
Hard
GeospatialGraphRouting
Not Started

Job Scheduler (like Cron)

DEEP DIVE
Medium
QueueDistributed SystemsReliability
Not Started

Online Code Judge (like LeetCode)

DEEP DIVE
Medium
QueueContainersSandboxing
Not Started

Collaborative Editor (Google Docs)

DEEP DIVE
Hard
CRDTWebSocketConflict Resolution
Not Started

Stock Exchange / Trading System

DEEP DIVE
Hard
Low LatencyMatching EngineFIFO Queue
Not Started

Food Delivery System (like DoorDash)

DEEP DIVE
Hard
GeospatialReal-timeMatching
Not Started

Distributed Logging System (like ELK)

DEEP DIVE
Medium
Log AggregationSearchTime-series
Not Started

Recommendation System

DEEP DIVE
Hard
MLCollaborative FilteringFeature Store
Not Started

Ad Serving System

DEEP DIVE
Hard
Real-time BiddingLow LatencyAuction
Not Started

Ride-Sharing Matching Algorithm

DEEP DIVE
Hard
GeospatialReal-timeOptimization
Not Started

Distributed Key-Value Store

MUST KNOW
Hard
Distributed SystemsConsistent HashingReplicationCAP Theorem
Not Started

Unique ID Generator

MUST KNOW
Medium
Distributed SystemsScalabilityCoordination
Not Started

Proximity Service

DEEP DIVE
Medium
GeospatialQuadtreeGeohashSearch
Not Started

Nearby Friends

DEEP DIVE
Hard
Real-timeWebSocketGeospatialPub/Sub
Not Started

Hotel Reservation System

SHOULD KNOW
Medium
BookingConcurrencyACIDInventory
Not Started

Distributed Email Service

DEEP DIVE
Hard
Distributed StorageSearchSMTPQueue
Not Started

S3-like Object Storage

DEEP DIVE
Hard
Distributed StorageErasure CodingMetadataDurability
Not Started

Real-time Gaming Leaderboard

SHOULD KNOW
Medium
RedisSorted SetReal-timeRanking
Not Started

Digital Wallet

DEEP DIVE
Hard
TransactionsACIDEvent SourcingDistributed Transactions
Not Started