https://sameeralam3127.github.io/system-design-365/ A structured, open knowledge base for system design interview prep: case studies, high-level and low-level design, patterns, trade-offs, and mock interviews. en https://sameeralam3127.github.io/system-design-365/case-studies/001-url-shortener/ https://sameeralam3127.github.io/system-design-365/case-studies/001-url-shortener/ Designing a read-heavy URL shortener at billions-of-URLs scale — Base62 encoding, distributed ID generation, caching, and CDN edge redirects. Sat, 01 Aug 2026 00:00:00 GMT https://sameeralam3127.github.io/system-design-365/case-studies/002-rate-limiter/ https://sameeralam3127.github.io/system-design-365/case-studies/002-rate-limiter/ Designing a distributed rate limiter for a multi-region API gateway — algorithm selection, Redis-backed token buckets, and fail-open semantics. Sat, 01 Aug 2026 00:00:00 GMT https://sameeralam3127.github.io/system-design-365/interview/interviewer-checklist/ https://sameeralam3127.github.io/system-design-365/interview/interviewer-checklist/ Use this during a mock interview to keep feedback concrete and consistent. https://sameeralam3127.github.io/system-design-365/interview/prompt-001-url-shortener/ https://sameeralam3127.github.io/system-design-365/interview/prompt-001-url-shortener/ Design a URL shortening service similar to Bitly. https://sameeralam3127.github.io/system-design-365/interview/prompt-002-notification-service/ https://sameeralam3127.github.io/system-design-365/interview/prompt-002-notification-service/ Design a notification service that can send email, SMS, and push notifications. https://sameeralam3127.github.io/system-design-365/interview/prompt-003-chat-system/ https://sameeralam3127.github.io/system-design-365/interview/prompt-003-chat-system/ Design a one-to-one and group chat system similar to WhatsApp or Slack messaging. https://sameeralam3127.github.io/system-design-365/interview/prompt-004-news-feed/ https://sameeralam3127.github.io/system-design-365/interview/prompt-004-news-feed/ Design a social media news feed similar to Facebook or Instagram home feed. https://sameeralam3127.github.io/system-design-365/interview/session-template/ https://sameeralam3127.github.io/system-design-365/interview/session-template/ - Date: - Interview type: HLD / LLD / mixed - Topic: - Duration: - Interviewer: - Candidate: https://sameeralam3127.github.io/system-design-365/security/python-before-your-code-runs/ https://sameeralam3127.github.io/system-design-365/security/python-before-your-code-runs/ Python does not always begin executing code at python app.py. The interpreter, package installer, test runner, and import system can all execute code before an application reaches its own entry point.