---
title: "Cosmos (@cosmologyisfun) | Hashnode"
description: "cosmology is fun. Read the latest articles by Cosmos on Hashnode."
url: "https://hashnode.com/@cosmologyisfun"
---

@cosmologyisfun

# Cosmos

@cosmologyisfun · Joined October 2025

cosmology is fun

### [Don't make these mistakes; otherwise, your cookies might break in production](https://cosmoscribe.hashnode.dev/dont-make-these-mistakes-otherwise-your-cookies-might-break-in-production?utm_source=hashnode&utm_medium=feed)

Look, if you've deployed something that was working perfectly on localhost and suddenly auth stops working in production, you're not alone. This is one of those bugs that doesn't throw a clear error.

9 min read · [cosmoscribe.hashnode.dev](https://cosmoscribe.hashnode.dev/dont-make-these-mistakes-otherwise-your-cookies-might-break-in-production?utm_source=hashnode&utm_medium=feed)

[Aug 10](https://hashnode.com/posts/dont-make-these-mistakes-otherwise-your-cookies-might-break-in-production/6a7a351197514a9fa25dfe4e)

### [Authentication Demystified: Every Login Method, Actually Explained](https://cosmoscribe.hashnode.dev/authentication-demystified-every-login-method-actually-explained?utm_source=hashnode&utm_medium=feed)

Basic auth, OAuth, passkeys, TOTP, magic links, SSO. Every major auth method with the real flow and real trade-offs. Here's the full breakdown.

13 min read · [cosmoscribe.hashnode.dev](https://cosmoscribe.hashnode.dev/authentication-demystified-every-login-method-actually-explained?utm_source=hashnode&utm_medium=feed)

[Jun 12](https://hashnode.com/posts/authentication-demystified-every-login-method-actually-explained/6a2bf45cb190448a018a1d14)

### [How WhatsApp Works Without Internet: Offline Messaging and Sync Explained](https://cosmoscribe.hashnode.dev/how-whatsapp-works-without-internet-offline-messaging-and-sync-explained?utm_source=hashnode&utm_medium=feed)

Send a WhatsApp message in airplane mode — it works instantly. Here's how local storage, message queues, and sync actually make that happen.

10 min read · [cosmoscribe.hashnode.dev](https://cosmoscribe.hashnode.dev/how-whatsapp-works-without-internet-offline-messaging-and-sync-explained?utm_source=hashnode&utm_medium=feed)

[May 31](https://hashnode.com/posts/how-whatsapp-works-without-internet-offline-messaging-and-sync-explained/6a1c7b06dbdc4ad3ed508643)

### [How Instagram Stores Your Reels, Photos, and Drafts Without Losing a Frame](https://cosmoscribe.hashnode.dev/how-instagram-stores-your-reels-photos-and-drafts-without-losing-a-frame?utm_source=hashnode&utm_medium=feed)

Mobile uploads are trickier than browser uploads. Pre-signed URLs, chunked streaming, local file writes — here's how it all fits together.

12 min read · [cosmoscribe.hashnode.dev](https://cosmoscribe.hashnode.dev/how-instagram-stores-your-reels-photos-and-drafts-without-losing-a-frame?utm_source=hashnode&utm_medium=feed)

[May 31](https://hashnode.com/posts/how-instagram-stores-your-reels-photos-and-drafts-without-losing-a-frame/6a1c20ad5f07fb89cc32b083)

### [React Navigation vs Expo Router: Which One Should You Actually Use?](https://cosmoscribe.hashnode.dev/react-navigation-vs-expo-router-which-one-should-you-actually-use?utm_source=hashnode&utm_medium=feed)

Discover the differences between React Navigation and Expo Router regarding routing, architecture, deep linking, and scalability for production apps.

16 min read · [cosmoscribe.hashnode.dev](https://cosmoscribe.hashnode.dev/react-navigation-vs-expo-router-which-one-should-you-actually-use?utm_source=hashnode&utm_medium=feed)

[May 23](https://hashnode.com/posts/react-navigation-vs-expo-router-which-one-should-you-actually-use/6a11370c1f237623ea686403)