How Instagram Stores Reels, Photos, and Drafts Behind the Scenes
Ever recorded a Reel, saved it as a draft, closed the app… and came back later to find it still there? Or noticed how videos load instantly even on slow internet? That’s not magic—it’s smart system design. Let’s walk through how apps like Instagram handle media storage, drafts, uploads, and delivery in a simple, practical […]
How WhatsApp Works Without Internet: Offline Messaging and Sync Explained
Have you ever sent a message in airplane mode… and it still appears instantly in your chat? No loading. No delay. Just “sent”. But in reality, there’s no internet. So what’s actually happening under the hood? Let’s break it down in a simple, system-design way. ✈️ A Simple Scenario: Sending a Message in Airplane Mode […]
How React Virtual DOM works under the Hood
When building modern web apps, performance matters. One of the biggest challenges in frontend development is efficiently updating the UI without slowing down the browser. React solves this problem using something called the Virtual DOM and updates data without reloading the whole website or app. React updates components that got data updates. Let’s understand it […]