All Articles (7 articles)

  • Design Real-Time Chat and Messaging

    System Design / System Design Problems 21 min read

    A comprehensive system design for real-time chat and messaging covering connection management, message delivery guarantees, ordering strategies, presence systems, group chat fan-out, and offline synchronization. This design addresses sub-second message delivery at WhatsApp/Discord scale (100B+ messages/day) with strong delivery guarantees and mobile-first offline resilience.

  • Design Search Autocomplete: Prefix Matching at Scale

    System Design / System Design Problems 18 min read

    A system design for search autocomplete (typeahead) covering prefix data structures, ranking algorithms, distributed architecture, and sub-100ms latency requirements. This design addresses the challenge of returning relevant suggestions within the user’s typing cadence—typically under 100ms—while handling billions of queries daily.

  • Design Collaborative Document Editing (Google Docs)

    System Design / System Design Problems 19 min read

    A comprehensive system design for real-time collaborative document editing covering synchronization algorithms, presence broadcasting, conflict resolution, storage patterns, and offline support. This design addresses sub-second convergence for concurrent edits while maintaining document history and supporting 10-50 simultaneous editors.

  • Design an Issue Tracker (Jira/Linear)

    System Design / System Design Problems 27 min read

    A comprehensive system design for an issue tracking and project management tool covering API design for dynamic workflows, efficient kanban board pagination, drag-and-drop ordering without full row updates, concurrent edit handling, and real-time synchronization. This design addresses the challenges of project-specific column configurations while maintaining consistent user-defined ordering across views.

  • Design a Flash Sale System

    System Design / System Design Problems 23 min read

    Building a system to handle millions of concurrent users competing for limited inventory during time-bounded sales events. Flash sales present a unique challenge: extreme traffic spikes (10-100x normal) concentrated in seconds, with zero tolerance for inventory errors. This design covers virtual waiting rooms, atomic inventory management, and asynchronous order processing.

  • URL Shortener Design: IDs, Storage, and Scale

    System Design / System Design Problems 1 min read

    A comprehensive guide to designing a scalable URL shortening service like bit.ly or TinyURL.

  • Design a Cookie Consent Service

    System Design / System Design Problems 25 min read

    Building a multi-tenant consent management platform that handles regulatory compliance (GDPR, CCPA, LGPD) at scale. Cookie consent services face unique challenges: read-heavy traffic patterns (every page load queries consent status), strict latency requirements (consent checks block page rendering), regulatory complexity across jurisdictions, and the need to merge anonymous visitor consent with authenticated user profiles. This design covers edge-cached consent delivery, anonymous-to-authenticated identity migration, and a multi-tenant architecture serving thousands of websites.