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Step through real-world distributed architectures progressively. Discover how high-scale microservices handle caching, sharding, replication, and concurrency.
System Design Blueprints
Architectural blueprints frequently asked in L4/L5/L6 Senior & Staff Software Engineer interviews.
Design a URL Shortener
TinyURL / Bitly Architecture
Architect a highly available URL shortening service handling 100M+ writes/month, low-latency 301/302 redirects, Base62 encoding, and cache eviction.
Distributed Rate Limiter
Token Bucket & Sliding Window Engine
Defend backend clusters against DDoS, abusive scraping, and API exhaustion using Redis Token Bucket, atomic Lua scripts, and sliding window logs.
Real-Time Chat Application
WhatsApp / Discord Scale Architecture
Scale bi-directional WebSocket connections, Redis Pub/Sub message fanout, Cassandra message archiving, and online/offline user presence.
Push Notification Service
Cross-Platform Notification Engine
High-throughput delivery pipeline for millions of iOS, Android, SMS, and Email alerts using RabbitMQ priority queues, worker fleets, and Dead Letter Queues (DLQ).
Distributed Job Queue
Asynchronous Task Processing Engine
Scale background computation with priority queues, worker pools, visibility timeouts, heartbeats, exponential backoff retries, and Dead Letter Queues (DLQ).