⏱ 7 min read Search suggestion (autocomplete) returns candidate completions for a partial query in under 100ms. The system must handle millions of prefix […] Read article

⏱ 8 min read API key management handles the full lifecycle of programmatic access credentials: creation, scoped authorization, usage tracking, rotation, and revocation. API Read article

⏱ 7 min read An invitation system lets existing users invite new users via unique links or codes, tracking who invited whom and rewarding Read article

⏱ 8 min read Multi-region replication keeps data available and performant for users worldwide by maintaining synchronized copies of data in multiple geographic regions. Read article

⏱ 7 min read A bulk email system sends millions of marketing or transactional emails to user segments, tracking delivery, opens, clicks, and unsubscribes. Read article

⏱ 7 min read Two-phase commit (2PC) is a distributed transaction protocol that ensures all participants in a multi-node operation either all commit or Read article

⏱ 7 min read Push notification token management handles the lifecycle of device tokens issued by APNs (Apple) and FCM (Google): storing them when Read article

⏱ 7 min read The inbox pattern is the receiving counterpart to the outbox pattern. Where the outbox ensures a service reliably publishes events Read article

⏱ 7 min read Service discovery lets microservices find each other without hardcoded IP addresses. In dynamic environments where containers start, stop, and move, Read article

⏱ 7 min read Pagination is not optional for any endpoint that returns a list — without it, a single request can return millions Read article

⏱ 7 min read Change Data Capture (CDC) streams every insert, update, and delete from a database as an ordered event log. Instead of Read article

⏱ 7 min read The saga pattern manages distributed transactions across multiple services by decomposing them into a sequence of local transactions, each publishing Read article

⏱ 7 min read Graceful Degradation — Low-Level Design Graceful degradation keeps a system functional when individual components fail, returning reduced-quality responses rather than Read article

⏱ 7 min read CDN Integration — Low-Level Design A CDN (Content Delivery Network) caches static assets and API responses at edge nodes close Read article

⏱ 7 min read Video Transcoding Pipeline — Low-Level Design A video transcoding pipeline converts uploaded video files into multiple formats and resolutions for Read article