How Big Tech Handles Millions of Requests with Caching | System Design EP 06

Database indexes made our queries fast, but what happens when 10,000 users hit your database simultaneously? Without caching, even the best-indexed databases will crash under high disk I/O. In Episode 5 of our System Design series in Tamil, we break down Caching from the ground up! We explore where caching lives—from CPU L1/L2/L3 caches and OS page caches all the way to Browser, CDN, and distributed caches like Redis. We dive deep into Cache-Aside, Write-Through, and Write-Back strategies, and introduce eviction policies (LRU, LFU). Note: The 4 pitfalls of distributed caching (Stampede, Penetration, Avalanche, and Crash) will be covered in Part 2! System Design Roadmap by Striver: https://takeuforward.org/system-desig... Check out my portfolio and projects: https://balajz.vercel.app/ CHAPTERS: 00:00 - The Traffic Surge Bottleneck 01:53 - What is Caching? (The Desk vs Library Analogy) 03:25 - Caching Everywhere: Hardware, OS & Browser Cache 06:07 - Distributed Cache, DB Buffer & Load Balancer 07:31 - CDN (Content Delivery Network) 08:29 - Core Mechanics: Cache Hit, Cache Miss & Cache-Aside 10:11 - Cache Writing Strategies: Write-Back vs Write-Through 13:10 - Eviction Policies: LRU & LFU 13:38 - Outro & Part 2 Teaser Connect With Me: GitHub: https://github.com/balajz LinkedIn:   / balajiz   LeetCode: https://leetcode.com/u/Balajix/ Website: https://balajz.vercel.app/