Challenges Catalog

System Architecture Problems

Choose a challenge, diagram your architecture on the Excalidraw canvas, and submit it for instant quantitative AI scoring.

16 Challenges
Level:
Domain:
Medium30-45 mins

Design a URL Shortener

Build a scalable URL shortening and redirection service like TinyURL or bit.ly.

#Hashing#Redis#NoSQL#Load Balancing#Analytics
Storage & CachingDesign System
Medium30-45 mins

Design an API Rate Limiter

Protect backend services from DDoS, brute-force attacks, and resource starvation.

#Token Bucket#Redis Lua#API Gateway#Distributed Locks
High Scale & WebDesign System
Hard45-60 mins

Design a Real-time Chat System

Architect a 1:1 and group messaging system like WhatsApp, Slack, or Discord.

#WebSockets#PubSub#Cassandra#Push Notifications#Presence
Real-Time & MessagingDesign System
Hard45-60 mins

Design a Video Streaming Platform

Architect a scalable video upload, transcoding, and playback platform like Netflix or YouTube.

#CDN#Transcoding#S3#HLS/DASH#Kafka Workers
Streaming & MediaDesign System
Hard45-60 mins

Design a Ride-Hailing Service

Build a location-tracking and driver-matching system like Uber or Lyft.

#Geospatial#H3/S2#WebSockets#Kafka#State Machine
Distributed SystemsDesign System
Hard45-60 mins

Design a Distributed Cache

Architect an in-memory key-value cache cluster with eviction and replication like Redis.

#Consistent Hashing#LRU Cache#Replication#In-Memory#Raft
Storage & CachingDesign System
Hard45-60 mins

Design a Social Network Feed

Build a high-throughput social feed generation system like Twitter/X or Facebook News Feed.

#Fanout Service#Redis ZSET#Kafka#Graph DB#Timeline
High Scale & WebDesign System
Hard45-60 mins

Design a Distributed Web Crawler

Architect a scalable web crawler capable of ingesting billions of pages for search engine indexing.

#URL Frontier#Bloom Filter#Politeness#DNS Cache#Bigtable
Distributed SystemsDesign System
Medium30-45 mins

Design a Notification Service

Build an enterprise multi-channel notification engine for Push, SMS, Email, and In-App alerts.

#Push Notifications#APNs/FCM#Kafka#Idempotency#Circuit Breaker
Real-Time & MessagingDesign System
Hard45-60 mins

Design Cloud File Storage

Architect a cloud file storage and cross-device sync service like Google Drive or Dropbox.

#Chunking#Delta Sync#S3#Metadata DB#Conflict Resolution
Storage & CachingDesign System
Medium30-45 mins

Design Search Autocomplete

Build a real-time typeahead search suggest system like Google or Amazon Autocomplete.

#Trie#In-Memory#Prefix Search#MapReduce#Edge Caching
Storage & CachingDesign System
Hard45-60 mins

Design a Flash Sale System

Architect an ultra-high concurrency ticketing and flash-sale checkout system.

#Redis Lua#Virtual Queue#Kafka#Inventory Lock#Concurrency
High Scale & WebDesign System
Hard45-60 mins

Design a Metrics Monitoring System

Architect a large-scale metrics ingestion, time-series storage, and alerting platform.

#TSDB#Time Series#Kafka#Flink#Alerting Engine
Distributed SystemsDesign System
Hard45-60 mins

Design Collaborative Document Editing

Build a real-time collaborative text editor like Google Docs or Notion.

#CRDT#Operational Transformation#WebSockets#PubSub#Concurrency
Real-Time & MessagingDesign System
Easy20-30 mins

Design a Distributed ID Generator

Generate globally unique, 64-bit time-sortable IDs at massive scale (Twitter Snowflake).

#Snowflake#Bit Manipulation#High Availability#Time Sortable
Distributed SystemsDesign System
Medium30-45 mins

Design a Real-time Gaming Leaderboard

Architect a real-time gaming leaderboard serving top scores and rank queries for millions of players.

#Redis Sorted Sets#ZSET#Gaming#Leaderboard#Sharding
Real-Time & MessagingDesign System