@hackproduct9: 🚀 Most engineers know these three words. Few know when to use each. A surprising number of system design interviews—and production outages—come down to confusing CDNs, Redis, and databases. Think of it this way: 🌍 CDN → Deliver content closer to users ⚡ Redis → Remember frequently used data for lightning-fast access 🗄️ Database → Store the source of truth permanently Instagram uses all three together: 📸 Photos & videos → CDN ❤️ Feed cache, sessions & counters → Redis 👤 Users, posts, comments & messages → Database The fastest systems don’t replace one with another—they combine all three in the right place. 📌 Save this cheat sheet for your next system design interview or while building your next app. 👇 Which topic should I simplify next? #SystemDesign #AIEngineering #SoftwareEngineering #Backend #DistributedSystems

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Saturday 25 July 2026 19:55:28 GMT