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@koushikkarmakar

Koushik Karmakar

@koushikkarmakar·Kolkata, West Bengal·Joined December 2025

Software Developer | Full-Stack MERN Developer

About

Trying to build more for future

Available for

Freelance work, Full Time job

Koushik Karmakar's blogs

DNS Work Processdnsworkprocess.hashnode.dev1 post

Hardware Networking Systemhardware-networking-system.hashnode.dev1 post

DNS Recordsdns-records-by-koushik.hashnode.dev1 post

cURL for Beginnerscurl-for-beginners-by-koushik.hashnode.dev1 post

Why Version Control Existswhy-version-control-exists-by-koushik.hashnode.dev1 post

About

Trying to build more for future

Available for

Freelance work, Full Time job

Koushik Karmakar's blogs

DNS Work Processdnsworkprocess.hashnode.dev1 post

Hardware Networking Systemhardware-networking-system.hashnode.dev1 post

DNS Recordsdns-records-by-koushik.hashnode.dev1 post

cURL for Beginnerscurl-for-beginners-by-koushik.hashnode.dev1 post

Why Version Control Existswhy-version-control-exists-by-koushik.hashnode.dev1 post

Articles Comments

Recently published

KKKoushik Karmakarinhow-instagram-stores-data.hashnode.dev·May 31 · 8 min read

How Instagram Stores Reels, Photos, and Drafts Behind the Scenes

You spend twenty minutes recording the perfect Reel, save it as a draft, close the app, go to sleep. Next morning — it's still there, exactly as you left it. That experience feels simple. Underneath i

KKKoushik Karmakarinoffline-messaging-and-sync.hashnode.dev·May 31 · 11 min read

How WhatsApp Works Without Internet: Offline Messaging and Sync Explained

You tap send. The message sits there with a single grey tick. You land, turn off airplane mode and suddenly everything swooshes through. How did WhatsApp do that? Most people assume messaging apps nee

KKKoushik Karmakarinfrontend-rendering-strategies-by-koushik.hashnode.dev·May 24 · 10 min read

Frontend Rendering Strategies Every Developer Must Understand

Every app you've ever built uses one of these. Here's what actually happens under the hood, why it matters at scale and how to pick the right one. A) Client-Side Rendering(CSR) The browser does all t

KKKoushik Karmakarinwhat-is-middleware-in-express-by-koushik.hashnode.dev·May 10 · 5 min read

What is Middleware in Express and How It Works

Every request that hits your Express server passes through a pipeline before it reaches your route handler. Middleware is what lives inside that pipeline. Think of it as a series of checkpoints, each

KKKoushik Karmakarinrest-api-design-made-simple-with-expressjs-by-koushik.hashnode.dev·May 10 · 5 min read

REST API Design Made Simple with Express.js

Every time your app loads data, submits a form or deletes a record, it is talking to an API. REST is the set of rules that makes that conversation clean and predictable. This guide shows you exactly h