---
title: "umer (@umerrahim) | Hashnode"
description: "Web developer. Read the latest articles by umer on Hashnode."
url: "https://hashnode.com/@umerrahim"
---

@umerrahim

# umer

@umerrahim · Joined January 2026

Web developer

[Website](https://www.umerrahim.me/)

### [How Transformers Work: From Text to ChatGPT](https://umerahim.hashnode.dev/how-transformers-work-from-text-to-chatgpt?utm_source=hashnode&utm_medium=feed)

Have you ever wondered how ChatGPT understands your questions and generates human-like responses? It all starts with text, but the model processes it through several mathematical steps. Let's understa

2 min read · [umerahim.hashnode.dev](https://umerahim.hashnode.dev/how-transformers-work-from-text-to-chatgpt?utm_source=hashnode&utm_medium=feed)

[Oct 18](https://hashnode.com/posts/how-transformers-work-from-text-to-chatgpt/6ad5158eceb820a098a708e7)

### [Understanding Asynchronous JavaScript and Promises](https://umerahim.hashnode.dev/understanding-asynchronous-javascript-and-promises?utm_source=hashnode&utm_medium=feed)

When I first started learning JavaScript, I noticed something confusing. Some lines of code executed immediately, while others ran after a delay. For example: console.log("Start"); setTimeout(() => {

3 min read · [umerahim.hashnode.dev](https://umerahim.hashnode.dev/understanding-asynchronous-javascript-and-promises?utm_source=hashnode&utm_medium=feed)

[Oct 18](https://hashnode.com/posts/understanding-asynchronous-javascript-and-promises/6ad5146751032cf1e17cca16)

### [\# Callbacks in JavaScript: Why They Exist](https://blogsbyumer.hashnode.dev/callbacks-in-javascript-why-they-exist?utm_source=hashnode&utm_medium=feed)

If you’ve been learning JavaScript, you’ve definitely seen the word callback. At first it feels like: Okay... it's a function... but why is it passed inside another function??? What is a Callback?

1 min read · [blogsbyumer.hashnode.dev](https://blogsbyumer.hashnode.dev/callbacks-in-javascript-why-they-exist?utm_source=hashnode&utm_medium=feed)

[Apr 17](https://hashnode.com/posts/callbacks-in-javascript-why-they-exist/69e1c379f27b011bda9cfbd6)

### [basic of async](https://umerahim.hashnode.dev/basic-of-async?utm_source=hashnode&utm_medium=feed)

asdasda

1 min read · [umerahim.hashnode.dev](https://umerahim.hashnode.dev/basic-of-async?utm_source=hashnode&utm_medium=feed)

[Apr 8](https://hashnode.com/posts/basic-of-async/69d68ccd707c1ce7685fba40)

### [Why Version Control Exists: The Pendrive Problem](https://versioncontrolexitance.hashnode.dev/why-version-control-exists-the-pendrive-problem?utm_source=hashnode&utm_medium=feed)

lets imagine a scenario if we have to develop an application.we are 3 developers with different task to do and we have to make a single application so what is the way to collabrate and to be syncbefore the version control software exists are are havi...

2 min read · [versioncontrolexitance.hashnode.dev](https://versioncontrolexitance.hashnode.dev/why-version-control-exists-the-pendrive-problem?utm_source=hashnode&utm_medium=feed)

[Feb 15](https://hashnode.com/posts/why-version-control-exists-the-pendrive-problem/69916b908a8f801ad7b1a1b7)