7 min read Two-Factor Authentication Backup Codes: Low-Level Design When a user loses access to their TOTP authenticator app, backup codes are the […] Read article
7 min read Push Notification System Low-Level Design A push notification system must reliably deliver time-sensitive messages to millions of devices across Android Read article
8 min read Data Retention Policy System Low-Level Design Every production database accumulates data that must eventually be purged, archived, or anonymized — Read article
11 min read Overview A file upload system must handle large binary transfers reliably — resuming interrupted uploads, scanning for malware, validating content Read article
9 min read Overview A content scheduler lets authors queue posts, stories, social updates, or any content entity for automatic publishing or unpublishing Read article
11 min read Overview A user segmentation system lets product and marketing teams define rule-based groups of users — “enterprise plan users who Read article
9 min read Overview A digest email system aggregates user-relevant events over a configurable time window and delivers a single summarized email rather Read article
7 min read Overview A price history system records product price changes over time, enables historical chart queries, and fires alerts when a Read article
8 min read Overview A token bucket rate limiter controls how many requests a client can make within a time period while allowing Read article
10 min read Distributed Tracing System: Low-Level Design A distributed tracing system records the journey of a request as it propagates through multiple Read article
10 min read Multi-Region Failover System: Low-Level Design A multi-region failover system routes traffic away from a failing region to a healthy standby, Read article
9 min read Tenant Isolation System: Low-Level Design A multi-tenant SaaS application serves many organizations (tenants) from a shared infrastructure. Tenant isolation ensures Read article
10 min read Saga Orchestration System: Low-Level Design A saga is a sequence of local transactions, each in a separate service, that together Read article
8 min read SLA Monitoring System: Low-Level Design An SLA monitoring system tracks whether a service is meeting its availability, latency, and error Read article
9 min read Canary Deployment System: Low-Level Design A canary deployment system routes a small fraction of production traffic to a new version Read article
