⏱ 6 min read Image Resizing Service — Low-Level Design An image resizing service generates and serves optimized image variants (thumbnails, responsive sizes, webp) […] Read article

⏱ 7 min read Caching Strategy — Low-Level Design A caching strategy determines what to cache, for how long, how to invalidate stale data, Read article

⏱ 7 min read Database Sharding — Low-Level Design Database sharding horizontally partitions data across multiple database instances, each holding a subset of the Read article

⏱ 6 min read Outbox Pattern — Low-Level Design The Transactional Outbox pattern ensures that database writes and message/event publishing happen atomically, without two-phase Read article

⏱ 7 min read Cursor Pagination — Low-Level Design Cursor pagination (also called keyset pagination) navigates large datasets stably and efficiently by using a Read article

⏱ 6 min read Faceted Search System — Low-Level Design A faceted search system lets users narrow results through multiple filter dimensions simultaneously — Read article

⏱ 6 min read Password Reset Flow — Low-Level Design A password reset flow lets users regain account access via a verified email link. Read article

⏱ 7 min read File Version Control System — Low-Level Design A file version control system tracks the history of changes to files, supports Read article

⏱ 6 min read User Blocking System — Low-Level Design A user blocking system prevents one user from seeing or interacting with another. It Read article

⏱ 7 min read Time Series Metrics System — Low-Level Design A time series metrics system stores and queries measurements that change over time: Read article

⏱ 6 min read Presence System — Low-Level Design A presence system tracks whether users are online, idle, or offline, and broadcasts status changes Read article

⏱ 7 min read Mentions and Notifications System — Low-Level Design A mentions system parses @username references in user content, identifies the mentioned users, Read article

⏱ 6 min read Live Comments System — Low-Level Design A live comments system streams new comments to all viewers of a piece of Read article

⏱ 6 min read Chunked File Upload System — Low-Level Design A chunked file upload system breaks large files into smaller pieces, uploads each Read article

⏱ 6 min read Event Deduplication System — Low-Level Design An event deduplication system ensures that duplicate events from at-least-once delivery queues are processed Read article