7 min read Feature Flag Service: Low-Level Design A feature flag service lets engineering teams ship code dark, run controlled rollouts, and flip […] Read article
7 min read CQRS Pattern: Low-Level Design CQRS (Command Query Responsibility Segregation) separates the write path — commands that mutate state — from Read article
7 min read Cache Invalidation System: Low-Level Design Cache invalidation is famously the hardest problem in computer science. A well-designed invalidation system must Read article
7 min read Referral Program System: Low-Level Design A referral program drives user acquisition by rewarding existing users who bring in new ones. Read article
6 min read Time-Series Aggregation System: Low-Level Design Storing raw metrics at full resolution is expensive at scale. A time-series aggregation system ingests Read article
6 min read Webhook Gateway: Low-Level Design A webhook gateway decouples internal event producers from external consumers. It accepts domain events, routes them Read article
9 min read Data Synchronization System: Low-Level Design A data synchronization system allows multiple devices or replicas to independently modify shared data and Read article
10 min read Incident Management System: Low-Level Design An incident management system ingests alerts from monitoring infrastructure, classifies them by severity, pages the Read article
8 min read Media Processing Pipeline: Low-Level Design A media processing pipeline handles the journey from raw video upload to CDN-delivered adaptive bitrate Read article
8 min read Notification Routing Engine: Low-Level Design A notification routing engine sits between the event source and the delivery channels (email, SMS, Read article
9 min read Permission Delegation System: Low-Level Design Permission delegation allows a user (delegator) to grant a subset of their own permissions to Read article
9 min read Content Recommendation System: Low-Level Design A content recommendation system must serve personalized item lists at low latency while continuously incorporating Read article
8 min read Threaded Comment System: Low-Level Design Threaded comment systems power discussion on news sites, forums, Reddit-style boards, and product pages. The Read article
8 min read Live Chat System: Low-Level Design A live chat system must maintain persistent WebSocket connections, fan out messages in milliseconds to Read article
8 min read Log Aggregation Pipeline: Low-Level Design A log aggregation pipeline collects structured logs from thousands of services, parses and enriches them, Read article
