●SYSTEM DESIGN SPECIFICATION REPOSITORY

Engineering Whitepapers & Specifications

In-depth architectural documentation for the world's most complex distributed platforms. Study real database schemas, back-of-the-envelope capacity math, API contracts, failure modes, and FAANG interview playbooks.

84+System Whitepapers
100%Production Math & Schemas
7 TiersPer Specification
45 MinInterview Scripts
⌕
FLAGSHIP ENGINEERING WHITEPAPERS

Deep-Dive System Specifications

Exhaustive technical analyses with production code, database DDL, and failure recovery matrices

💳
FINANCIAL INFRASTRUCTURE

Stripe

Zero Double-Charge Guarantee

PCI-DSS tokenization vaults, distributed idempotency mutexes, machine-learning fraud scoring (Radar <45ms), and balanced double-entry accounting ledgers.

600 QPS avg · 6,000 QPS peak · $1.0T+ Annual VolumeRead Whitepaper →
🚗
GEOSPATIAL REAL-TIME

Uber

1.25M GPS Pings / Sec

O(1) Uber H3 hexagonal spatial indexing, Redis Geo sorted sets, two-phase candidate matching, dynamic surge pricing algorithms, and trip finite state machines.

1.25M updates/sec · sub-15ms matching · 5M concurrent driversRead Whitepaper →
🎬
GLOBAL VIDEO STREAMING

Netflix

100+ Tbps Egress

Decoupled AWS cloud control plane from Open Connect ISP caching appliances, parallel chunk transcoding with Archer, and client-driven adaptive bitrate algorithms.

100+ Tbps peak · 260M subscribers · masterless CassandraRead Whitepaper →
💬
HIGH-CONCURRENCY CHAT

WhatsApp

C1000K FreeBSD Tuning

Erlang/OTP BEAM lightweight actor processes (2M+ connections per box), Signal Protocol Double Ratchet E2EE, in-memory Mnesia routing, and ephemeral storage.

100B messages/day · 2.5B users · 2.5KB RAM per sessionRead Whitepaper →
📸
ASYMMETRICAL SOCIAL GRAPH

Instagram

Hybrid Push/Pull Fan-Out

Resolving the Celebrity Problem in news feed generation, TAO distributed graph caching, Haystack/Needle blob storage, and 64-bit distributed Snowflake IDs.

100M uploads/day · 10B feed views/day · 100:1 read:writeRead Whitepaper →
🤖
AI & LLM INFERENCE

ChatGPT

PagedAttention Virtual Paging

vLLM PagedAttention virtual memory management for GPU HBM, HTTP/2 Server-Sent Events token streaming, continuous iteration batching, and prompt prefix caching.

TTFT < 350ms · ITL < 30ms · 4x GPU throughput via vLLMRead Whitepaper →
DOCUMENTATION CATALOG

All System Design Specifications(84)

🚗

Uber

DEEP DIVE
Ride & Transport

Real-time ride matching at global planetary scale

SLA99.99%
SERVICES12
TIERS6 Tiers
Geohashing & H3WebSocketsEvent Sourcing
📖 Read Specification⚡ Blueprint
🎬

Netflix

DEEP DIVE
Video & Streaming

Streaming billions of hours of 4K video to 260M+ subscribers

SLA99.97%
SERVICES15
TIERS6 Tiers
Adaptive Bitrate Streaming (ABR)Open Connect ISP CDNMassively Parallel Transcoding
📖 Read Specification⚡ Blueprint
💳

Stripe

DEEP DIVE
Payments

Global financial infrastructure processing hundreds of billions

SLA99.9999%
SERVICES10
TIERS6 Tiers
Distributed Idempotency KeysDouble-Entry BookkeepingPCI-DSS Tokenization
📖 Read Specification⚡ Blueprint
💬

WhatsApp

DEEP DIVE
Messaging

100 Billion+ messages per day on minimal infrastructure

SLA99.9%
SERVICES8
TIERS6 Tiers
WebSockets & Long-Lived ConnectionsErlang BEAM Concurrency ModelEnd-to-End Encryption (Signal Protocol)
📖 Read Specification⚡ Blueprint
📸

Instagram

DEEP DIVE
Social Media

2 Billion+ users: solving the social media fan-out challenge

SLA99.95%
SERVICES14
TIERS6 Tiers
Fan-Out on Write vs Fan-Out on ReadHybrid Fan-Out ArchitectureHaystack Small-File Storage
📖 Read Specification⚡ Blueprint
🛒

Amazon

E-Commerce

The everything store at planetary scale — handling Black Friday rushes

SLA99.99%
SERVICES20
TIERS6 Tiers
Distributed Saga PatternOptimistic Concurrency ControlTwo-Phase Commit vs Saga
📖 Read Specification⚡ Blueprint
🤖

ChatGPT / AI Assistant

DEEP DIVE
AI Products

LLM inference at global scale — token streaming & RAG architecture

SLA99.9%
SERVICES12
TIERS6 Tiers
Transformer Auto-Regressive DecodingPagedAttention & KV CacheServer-Sent Events (SSE) Streaming
📖 Read Specification⚡ Blueprint
🎵

Spotify

Music

Music streaming with hyper-personalized Discover Weekly algorithms

SLA99.9%
SERVICES10
TIERS6 Tiers
Sub-50ms Audio Pre-FetchingCollaborative Filtering (Matrix Factorization)Royalty Calculation Event Sourcing
📖 Read Specification⚡ Blueprint
🍕

Zomato

Food Delivery

Food delivery and restaurant discovery for 300,000+ restaurants

SLA99.9%
SERVICES11
TIERS6 Tiers
Three-Sided Marketplace DynamicsOrder State MachineGeospatial Dispatch Optimization
📖 Read Specification⚡ Blueprint
🚕

Ola

Ride & Transport

India's ride-hailing giant

SLA99.9%
SERVICES10
TIERS6 Tiers
Geohashing & H3Real-time Location StreamsMatching Algorithm
📖 Read Specification⚡ Blueprint
🩷

Lyft

Ride & Transport

Ride-sharing across North America

SLA99.9%
SERVICES9
TIERS6 Tiers
Geohashing & H3Real-time Location StreamsMatching Algorithm
📖 Read Specification⚡ Blueprint
🛵

Rapido

Ride & Transport

Bike taxis for urban India

SLA99.8%
SERVICES8
TIERS6 Tiers
Geohashing & H3Real-time Location StreamsMatching Algorithm
📖 Read Specification⚡ Blueprint
🌿

Grab

Ride & Transport

Southeast Asia's super-app

SLA99.9%
SERVICES15
TIERS6 Tiers
Geohashing & H3Real-time Location StreamsMatching Algorithm
📖 Read Specification⚡ Blueprint
🚙

BlaBlaCar

Ride & Transport

Long-distance carpooling

SLA99.5%
SERVICES7
TIERS6 Tiers
Geohashing & H3Real-time Location StreamsMatching Algorithm
📖 Read Specification⚡ Blueprint
🛵

Swiggy

Food Delivery

Food, grocery & more delivery

SLA99.9%
SERVICES12
TIERS6 Tiers
Order State MachineThree-Sided MarketplaceReal-Time Tracking
📖 Read Specification⚡ Blueprint
🥡

Uber Eats

Food Delivery

Food delivery from Uber

SLA99.9%
SERVICES10
TIERS6 Tiers
Order State MachineThree-Sided MarketplaceReal-Time Tracking
📖 Read Specification⚡ Blueprint
🍔

DoorDash

Food Delivery

On-demand delivery across US

SLA99.9%
SERVICES11
TIERS6 Tiers
Order State MachineThree-Sided MarketplaceReal-Time Tracking
📖 Read Specification⚡ Blueprint
🦘

Deliveroo

Food Delivery

Premium food delivery UK/EU

SLA99.9%
SERVICES10
TIERS6 Tiers
Order State MachineThree-Sided MarketplaceReal-Time Tracking
📖 Read Specification⚡ Blueprint
🛍️

Flipkart

E-Commerce

India's largest e-commerce

SLA99.99%
SERVICES18
TIERS6 Tiers
Distributed Saga PatternOptimistic LockingPayment Idempotency
📖 Read Specification⚡ Blueprint
🏷️

eBay

E-Commerce

Marketplace for buying and selling

SLA99.9%
SERVICES14
TIERS6 Tiers
Distributed Saga PatternOptimistic LockingPayment Idempotency
📖 Read Specification⚡ Blueprint
🏪

Shopify

E-Commerce

Commerce platform for everyone

SLA99.99%
SERVICES16
TIERS6 Tiers
Distributed Saga PatternOptimistic LockingPayment Idempotency
📖 Read Specification⚡ Blueprint
🎨

Etsy

E-Commerce

Marketplace for handmade & vintage

SLA99.9%
SERVICES10
TIERS6 Tiers
Distributed Saga PatternOptimistic LockingPayment Idempotency
📖 Read Specification⚡ Blueprint
🐦

Twitter / X

Social Media

Real-time public conversation

SLA99.9%
SERVICES16
TIERS6 Tiers
Hybrid Fan-OutFeed Pre-ComputationSmall-File Storage
📖 Read Specification⚡ Blueprint
👤

Facebook

Social Media

3B+ user social network

SLA99.99%
SERVICES25
TIERS6 Tiers
Hybrid Fan-OutFeed Pre-ComputationSmall-File Storage
📖 Read Specification⚡ Blueprint
🤖

Reddit

Social Media

Front page of the internet

SLA99.9%
SERVICES12
TIERS6 Tiers
Hybrid Fan-OutFeed Pre-ComputationSmall-File Storage
📖 Read Specification⚡ Blueprint
📌

Pinterest

Social Media

Visual discovery and bookmarking

SLA99.9%
SERVICES10
TIERS6 Tiers
Hybrid Fan-OutFeed Pre-ComputationSmall-File Storage
📖 Read Specification⚡ Blueprint
🎵

TikTok

Social Media

Short-form video with viral algorithm

SLA99.9%
SERVICES18
TIERS6 Tiers
Hybrid Fan-OutFeed Pre-ComputationSmall-File Storage
📖 Read Specification⚡ Blueprint
✈️

Telegram

Messaging

Fast, secure messaging

SLA99.9%
SERVICES8
TIERS6 Tiers
WebSockets & Long Lived TCPErlang BEAM ConcurrencyEnd-to-End Encryption
📖 Read Specification⚡ Blueprint
💼

Slack

Messaging

Work messaging for teams

SLA99.99%
SERVICES12
TIERS6 Tiers
WebSockets & Long Lived TCPErlang BEAM ConcurrencyEnd-to-End Encryption
📖 Read Specification⚡ Blueprint
🎮

Discord

Messaging

Voice, video & text for communities

SLA99.9%
SERVICES14
TIERS6 Tiers
WebSockets & Long Lived TCPErlang BEAM ConcurrencyEnd-to-End Encryption
📖 Read Specification⚡ Blueprint
🔒

Signal

Messaging

Privacy-first encrypted messaging

SLA99.5%
SERVICES6
TIERS6 Tiers
WebSockets & Long Lived TCPErlang BEAM ConcurrencyEnd-to-End Encryption
📖 Read Specification⚡ Blueprint
▶️

YouTube

Video & Streaming

500 hours of video uploaded per minute

SLA99.9%
SERVICES18
TIERS6 Tiers
Adaptive Bitrate StreamingOpen Connect CDNParallel Transcoding DAG
📖 Read Specification⚡ Blueprint
🎮

Twitch

Video & Streaming

Live streaming for gamers

SLA99.9%
SERVICES12
TIERS6 Tiers
Adaptive Bitrate StreamingOpen Connect CDNParallel Transcoding DAG
📖 Read Specification⚡ Blueprint
🎭

Prime Video

Video & Streaming

Amazon's global streaming service

SLA99.9%
SERVICES14
TIERS6 Tiers
Adaptive Bitrate StreamingOpen Connect CDNParallel Transcoding DAG
📖 Read Specification⚡ Blueprint
🏏

Hotstar / JioCinema

Video & Streaming

Billion-viewer IPL streams

SLA99.5%
SERVICES12
TIERS6 Tiers
Adaptive Bitrate StreamingOpen Connect CDNParallel Transcoding DAG
📖 Read Specification⚡ Blueprint
🍎

Apple Music

Music

Music streaming by Apple

SLA99.9%
SERVICES8
TIERS6 Tiers
Collaborative Filtering MLPre-Fetching for Zero-Gap AudioEvent Sourced Royalties
📖 Read Specification⚡ Blueprint
☁️

SoundCloud

Music

Creator-first music platform

SLA99.5%
SERVICES8
TIERS6 Tiers
Collaborative Filtering MLPre-Fetching for Zero-Gap AudioEvent Sourced Royalties
📖 Read Specification⚡ Blueprint
🎶

JioSaavn

Music

India's biggest music app

SLA99.8%
SERVICES8
TIERS6 Tiers
Collaborative Filtering MLPre-Fetching for Zero-Gap AudioEvent Sourced Royalties
📖 Read Specification⚡ Blueprint
⚡

Razorpay

Payments

India's leading payment gateway

SLA99.99%
SERVICES10
TIERS6 Tiers
Idempotency KeysDouble-Entry LedgerPCI-DSS Tokenization
📖 Read Specification⚡ Blueprint
💰

Paytm

Payments

India's digital payments super-app

SLA99.9%
SERVICES15
TIERS6 Tiers
Idempotency KeysDouble-Entry LedgerPCI-DSS Tokenization
📖 Read Specification⚡ Blueprint
📱

PhonePe

Payments

UPI-based payments for India

SLA99.99%
SERVICES10
TIERS6 Tiers
Idempotency KeysDouble-Entry LedgerPCI-DSS Tokenization
📖 Read Specification⚡ Blueprint
🅿️

PayPal

Payments

Global digital payments pioneer

SLA99.9%
SERVICES14
TIERS6 Tiers
Idempotency KeysDouble-Entry LedgerPCI-DSS Tokenization
📖 Read Specification⚡ Blueprint
📊

Zerodha

Trading

India's largest stock broker

SLA99.99%
SERVICES12
TIERS6 Tiers
In-Memory Order BooksLMAX Disruptor PatternUltra-Low Latency C++
📖 Read Specification⚡ Blueprint
🏹

Robinhood

Trading

Commission-free stock trading

SLA99.9%
SERVICES12
TIERS6 Tiers
In-Memory Order BooksLMAX Disruptor PatternUltra-Low Latency C++
📖 Read Specification⚡ Blueprint
🪙

Coinbase

Trading

Crypto exchange at scale

SLA99.9%
SERVICES14
TIERS6 Tiers
In-Memory Order BooksLMAX Disruptor PatternUltra-Low Latency C++
📖 Read Specification⚡ Blueprint
₿

Binance

Trading

World's largest crypto exchange

SLA99.9%
SERVICES16
TIERS6 Tiers
In-Memory Order BooksLMAX Disruptor PatternUltra-Low Latency C++
📖 Read Specification⚡ Blueprint
🏠

Airbnb

Travel

Home-sharing marketplace worldwide

SLA99.9%
SERVICES14
TIERS6 Tiers
Distributed Availability LocksHigh-Concurrency BookingSearch Cache Invalidation
📖 Read Specification⚡ Blueprint
🏨

Booking.com

Travel

Global accommodation booking

SLA99.99%
SERVICES16
TIERS6 Tiers
Distributed Availability LocksHigh-Concurrency BookingSearch Cache Invalidation
📖 Read Specification⚡ Blueprint
✈️

Expedia

Travel

Travel booking platform

SLA99.9%
SERVICES14
TIERS6 Tiers
Distributed Availability LocksHigh-Concurrency BookingSearch Cache Invalidation
📖 Read Specification⚡ Blueprint
🌍

Skyscanner

Travel

Global flight search engine

SLA99.9%
SERVICES10
TIERS6 Tiers
Distributed Availability LocksHigh-Concurrency BookingSearch Cache Invalidation
📖 Read Specification⚡ Blueprint
⚡

Blinkit

Delivery & Logistics

10-minute grocery delivery

SLA99.5%
SERVICES10
TIERS6 Tiers
Traveling Salesperson RoutingWarehouse Robotic DispatchReal-Time Vehicle Tracking
📖 Read Specification⚡ Blueprint
🚀

Zepto

Delivery & Logistics

Fastest grocery delivery in India

SLA99.5%
SERVICES10
TIERS6 Tiers
Traveling Salesperson RoutingWarehouse Robotic DispatchReal-Time Vehicle Tracking
📖 Read Specification⚡ Blueprint
📦

FedEx

Delivery & Logistics

Global express shipping

SLA99.9%
SERVICES18
TIERS6 Tiers
Traveling Salesperson RoutingWarehouse Robotic DispatchReal-Time Vehicle Tracking
📖 Read Specification⚡ Blueprint
🚛

Delhivery

Delivery & Logistics

India's largest logistics network

SLA99.5%
SERVICES14
TIERS6 Tiers
Traveling Salesperson RoutingWarehouse Robotic DispatchReal-Time Vehicle Tracking
📖 Read Specification⚡ Blueprint
🔍

Google Search

Search

Index of the entire internet

SLA99.999%
SERVICES20
TIERS6 Tiers
Inverted IndexingBM25 & TF-IDF RankingDistributed Sharding
📖 Read Specification⚡ Blueprint
🔎

Elasticsearch

Search

Distributed search & analytics

SLA99.9%
SERVICES6
TIERS6 Tiers
Inverted IndexingBM25 & TF-IDF RankingDistributed Sharding
📖 Read Specification⚡ Blueprint
🔹

Algolia

Search

Search-as-a-service API

SLA99.99%
SERVICES8
TIERS6 Tiers
Inverted IndexingBM25 & TF-IDF RankingDistributed Sharding
📖 Read Specification⚡ Blueprint
📁

Google Drive

Cloud Storage

Cloud file storage for billions

SLA99.9%
SERVICES10
TIERS6 Tiers
Content-Addressed ChunkingData DeduplicationMetadata vs Block Separation
📖 Read Specification⚡ Blueprint
📦

Dropbox

Cloud Storage

File sync and sharing pioneer

SLA99.9%
SERVICES10
TIERS6 Tiers
Content-Addressed ChunkingData DeduplicationMetadata vs Block Separation
📖 Read Specification⚡ Blueprint
☁️

iCloud

Cloud Storage

Apple's cloud ecosystem

SLA99.9%
SERVICES10
TIERS6 Tiers
Content-Addressed ChunkingData DeduplicationMetadata vs Block Separation
📖 Read Specification⚡ Blueprint
🖼️

Google Photos

Cloud Storage

Unlimited photo backup with AI

SLA99.9%
SERVICES12
TIERS6 Tiers
Content-Addressed ChunkingData DeduplicationMetadata vs Block Separation
📖 Read Specification⚡ Blueprint
🎮

Steam

Gaming

World's largest PC gaming platform

SLA99.9%
SERVICES16
TIERS6 Tiers
Deterministic State SyncLag Compensation & PredictionReal-Time Matchmaking
📖 Read Specification⚡ Blueprint
🎯

PUBG

Gaming

Battle royale at global scale

SLA99.5%
SERVICES14
TIERS6 Tiers
Deterministic State SyncLag Compensation & PredictionReal-Time Matchmaking
📖 Read Specification⚡ Blueprint
🏗️

Fortnite

Gaming

100-player real-time battle royale

SLA99.5%
SERVICES16
TIERS6 Tiers
Deterministic State SyncLag Compensation & PredictionReal-Time Matchmaking
📖 Read Specification⚡ Blueprint
🎮

PlayStation Network

Gaming

Gaming platform for 100M+ players

SLA99.9%
SERVICES18
TIERS6 Tiers
Deterministic State SyncLag Compensation & PredictionReal-Time Matchmaking
📖 Read Specification⚡ Blueprint
🔮

Perplexity AI

AI Products

AI-powered search with citations

SLA99.5%
SERVICES10
TIERS6 Tiers
Transformer Auto-Regressive DecodingPagedAttention & KV CacheSSE Token Streaming
📖 Read Specification⚡ Blueprint
🎨

AI Image Generation

AI Products

Diffusion models at scale

SLA99%
SERVICES8
TIERS6 Tiers
Transformer Auto-Regressive DecodingPagedAttention & KV CacheSSE Token Streaming
📖 Read Specification⚡ Blueprint
🧠

RAG System

AI Products

Retrieval-Augmented Generation

SLA99.5%
SERVICES8
TIERS6 Tiers
Transformer Auto-Regressive DecodingPagedAttention & KV CacheSSE Token Streaming
📖 Read Specification⚡ Blueprint
🗺️

Google Maps

Maps & Location

Global mapping and navigation

SLA99.9%
SERVICES20
TIERS6 Tiers
Tile Server HierarchiesDijkstra / A* Shortest PathMap Matching GPS Snapping
📖 Read Specification⚡ Blueprint
📍

Mapbox

Maps & Location

Maps API for developers

SLA99.9%
SERVICES10
TIERS6 Tiers
Tile Server HierarchiesDijkstra / A* Shortest PathMap Matching GPS Snapping
📖 Read Specification⚡ Blueprint
🏏

Cricbuzz

Sports & Live Events

Real-time cricket scores for 100M+

SLA99.5%
SERVICES8
TIERS6 Tiers
Live Event StreamingCache Invalidation Under SpikesWebSocket Score Push
📖 Read Specification⚡ Blueprint
🏀

ESPN

Sports & Live Events

Sports news and live scores

SLA99.9%
SERVICES12
TIERS6 Tiers
Live Event StreamingCache Invalidation Under SpikesWebSocket Score Push
📖 Read Specification⚡ Blueprint
⚽

Live Scores Platform

Sports & Live Events

Global sports event streaming

SLA99%
SERVICES8
TIERS6 Tiers
Live Event StreamingCache Invalidation Under SpikesWebSocket Score Push
📖 Read Specification⚡ Blueprint
📝

Google Docs

Collaboration

Real-time collaborative editing

SLA99.99%
SERVICES10
TIERS6 Tiers
Operational Transformation (OT)Conflict-Free Replicated Data Types (CRDT)WebSocket P2P Sync
📖 Read Specification⚡ Blueprint
⬛

Notion

Collaboration

All-in-one workspace

SLA99.9%
SERVICES10
TIERS6 Tiers
Operational Transformation (OT)Conflict-Free Replicated Data Types (CRDT)WebSocket P2P Sync
📖 Read Specification⚡ Blueprint
🎨

Figma

Collaboration

Collaborative design tool

SLA99.9%
SERVICES12
TIERS6 Tiers
Operational Transformation (OT)Conflict-Free Replicated Data Types (CRDT)WebSocket P2P Sync
📖 Read Specification⚡ Blueprint
📹

Zoom

Collaboration

Video conferencing at scale

SLA99.9%
SERVICES14
TIERS6 Tiers
Operational Transformation (OT)Conflict-Free Replicated Data Types (CRDT)WebSocket P2P Sync
📖 Read Specification⚡ Blueprint
🔐

Auth / Identity System

Security

Authentication & authorization

SLA99.99%
SERVICES8
TIERS6 Tiers
Zero Trust ArchitectureJWT Token RotationToken Bucket Rate Limiting
📖 Read Specification⚡ Blueprint
🚨

Fraud Detection

Security

ML-based fraud prevention

SLA99.9%
SERVICES8
TIERS6 Tiers
Zero Trust ArchitectureJWT Token RotationToken Bucket Rate Limiting
📖 Read Specification⚡ Blueprint
🛡️

Rate Limiting System

Security

API rate limiting at scale

SLA99.99%
SERVICES4
TIERS6 Tiers
Zero Trust ArchitectureJWT Token RotationToken Bucket Rate Limiting
📖 Read Specification⚡ Blueprint
🏦

Neo Bank

Banking & Finance

Digital-first banking

SLA99.99%
SERVICES14
TIERS6 Tiers
ACID Distributed TransactionsImmutable Audit TrailsTwo-Phase Commit
📖 Read Specification⚡ Blueprint
💸

UPI System

Banking & Finance

India's real-time payment rails

SLA99.99%
SERVICES10
TIERS6 Tiers
ACID Distributed TransactionsImmutable Audit TrailsTwo-Phase Commit
📖 Read Specification⚡ Blueprint
🏧

ATM Network

Banking & Finance

Global ATM infrastructure

SLA99.5%
SERVICES8
TIERS6 Tiers
ACID Distributed TransactionsImmutable Audit TrailsTwo-Phase Commit
📖 Read Specification⚡ Blueprint
💳

Credit Card System

Banking & Finance

Card network & processing

SLA99.999%
SERVICES12
TIERS6 Tiers
ACID Distributed TransactionsImmutable Audit TrailsTwo-Phase Commit
📖 Read Specification⚡ Blueprint