Product Systems
Full product designs: search, video, ride-sharing, ads, and more.
These are the interview problems where user-facing product behavior, data modeling, realtime updates, abuse prevention, ranking, and operations all intersect.
Each page is a guided placeholder that frames the architecture, key decisions, and likely interview angles before the interactive deep dive exists.
Start from the branch overview, then drill into one problem at a time and compare trade-offs across neighboring designs instead of memorizing isolated answers.
Pick a design problem
Design a News Feed
MediumMaster the architecture behind Facebook, Twitter, and LinkedIn feeds from fan-out strategies and ranking to realtime delivery at scale.
Design a Payment System
HardDesign a production-grade payment system with idempotency, double-entry ledgers, refunds, reconciliation, PCI compliance, and high-volume transaction processing.
Design a Web Crawler
MediumArchitect a distributed web crawler that discovers, downloads, and deduplicates billions of pages with politeness rules and frontier scheduling.
Design Instagram / Photo Sharing
MediumArchitect a photo-sharing platform with upload pipelines, CDN distribution, fan-out strategies, social graph storage, and billions of photos.
Design YouTube / Video Platform
HardArchitect a video platform from upload and transcoding pipelines to adaptive bitrate streaming, recommendation engines, and massive daily view counts.
Design a Ride-Sharing Platform
HardArchitect Uber or Lyft from realtime location tracking and geospatial indexing to driver-rider matching, ETA calculation, and surge pricing.
Design a Hotel/Flight Booking System
HardArchitect a booking platform with inventory management, search pipelines, dynamic pricing, double-booking prevention, and payment integration.
Design an Ad Click Aggregator
MediumArchitect a realtime ad click aggregation system with event collection, stream processing, deduplication, time-window aggregation, fraud detection, and reconciliation.
Design E-commerce Search
MediumArchitect a product search system with query understanding, faceted filtering, learning-to-rank, personalization, autocomplete, and large catalog scale.