Topics
Explore the systems we're writing about. Read a published article, see what's being researched, or look ahead to planned topics.
- Published
Design Distributed Message Queue like Kafka
A broker that survives crashes without losing events.
- Published
Design File Sharing System like Dropbox
When two offline edits collide, what survives?
- Published
Design Leaderboard
Rank scores without recalculating everyone.
- Published
Design a Metrics Monitoring System
Spot trouble before users notice.
- Published
Design Email Service
Deliver billions of emails across petabyte mailboxes with zero data loss.
- Researching
Design Click Aggregator
Billions of clicks, one trustworthy number.
- Planned
Design Rate Limiter
Stop bursts without punishing real users.
- Planned
Design Distributed Cache
When caches disagree, which answer wins?
- Planned
Design URL Shortener like TinyURL
Tiny links, huge traffic, no wrong destination.
- Planned
Design Text Storage Service like Pastebin
A viral paste that never slows down.
- Planned
Design Content Delivery Network (CDN)
Fresh content, milliseconds from every visitor.
- Planned
Design Parking Garage
Every parking ticket hides a state machine.
- Planned
Design Vending Machine
Coins, stock, refunds, and one tricky machine.
- Planned
Design Distributed Key-Value Store
Find any key as machines come and go.
- Planned
Design Distributed Job Scheduler
Run every job once, even after failure.
- Planned
Design Authentication System
Recognize users without making login painful.
- Planned
Design Unified Payments Interface (UPI)
Real-time money moves when banks must agree.
- Planned
Design Instagram
The endless feed that stays fresh.
- Planned
Design Tinder
Two swipes, one private match.
- Planned
Design WhatsApp
Private messages that arrive in order.
- Planned
Design Facebook
Who decides your next feed story?
- Planned
Design Twitter
One post, millions of timelines, no meltdown.
- Planned
Design Reddit
Votes turn chaos into a conversation.
- Planned
Design Netflix
A movie that starts on a shaky network.
- Planned
Design YouTube
What happens between upload and play?
- Planned
Design Google Search
Turn the web into an answer.
- Planned
Design E-commerce Store like Amazon
Reserve the last item before someone else.
- Planned
Design Spotify
Music follows you across every device.
- Planned
Design TikTok
The loop behind just one more video.
- Planned
Design Shopify
Millions of stores, one reliable platform.
- Planned
Design Airbnb
Stop two travellers booking the same room.
- Planned
Design Autocomplete for Search Engines
Suggestions before your final keystroke.
- Planned
Design Flight Booking System
Last seats, thousands of searches, one truth.
- Planned
Design Hotel Reservation System
Hold rooms long enough to complete payment.
- Planned
Design Online Code Editor
Run untrusted code without escape.
- Planned
Design Stock Exchange System
Fair order matching where milliseconds matter.
- Planned
Design an Analytics Platform (Metrics & Logging)
Find one useful signal in an event flood.
- Planned
Design Notification Service
Deliver one urgent ping at the right moment.
- Planned
Design Payment System
What does paid mean after a network failure?
- Planned
Design Location Based Service like Yelp / Proximity service
Nearby results without oversharing your location.
- Planned
Design Uber
Match moving riders and drivers in real time.
- Planned
Design Food Delivery App like Doordash
Kitchen, courier, and customer in sync.
- Planned
Design Google Docs
Two writers, one document, no lost words.
- Planned
Design Google Maps
Roads and traffic become one useful route.
- Planned
Design Zoom
Many faces, many networks, one conversation.
- Planned
Design Ticket Booking System like BookMyShow
Sell one hot seat only once.
- Planned
Design Distributed Web Crawler
Explore the web without crawling it twice.
- Planned
Design Code Deployment System
Ship fast without spreading a bad release.
- Planned
Design Distributed Cloud Storage like S3
Files that survive machine and rack failures.
- Planned
Design Distributed Locking Service
Who owns the key when clocks disagree?
- Planned
Design Digital Wallet
Balances that stay true across many devices.
- Planned
Design Nearby Friends
Friends nearby without broadcasting their location.
- Planned
Design Consistent Hashing
Add a server without losing the map.
- Planned
Design IRCTC
Scarce seats, rush-hour demand, fair bookings.
- Planned
Design Shared Counter
Many writers, one number, no lost increments.
- Planned
Design ID Generator
Unique IDs everywhere, without central waiting.