---
title: "Arun Kumar (@importarun) | Hashnode"
description: "In pursuit of the signal within the noise. Read the latest articles by Arun Kumar on Hashnode."
url: "https://hashnode.com/@importarun"
---

@importarun

# Arun Kumar

@importarun · Chennai, Tamil Nadu, India · Joined September 2025

In pursuit of the signal within the noise.

[Website](https://arunkumarm-git.github.io/)

### [Zero to Neuron Series 9: Vision Transformer by Hand: Every Number, Every Matrix, Every "Why"](https://importarun-dl.hashnode.dev/zero-to-neuron-series-9-vision-transformer-by-hand-every-number-every-matrix-every-why?utm_source=hashnode&utm_medium=feed)

A complete numerical walkthrough for CNN practitioners stepping into the world of Transformers — from raw pixels to final class probabilities, with no hand-waving allowed. You've studied CNNs. You kn

35 min read · [importarun-dl.hashnode.dev](https://importarun-dl.hashnode.dev/zero-to-neuron-series-9-vision-transformer-by-hand-every-number-every-matrix-every-why?utm_source=hashnode&utm_medium=feed)

[May 12](https://hashnode.com/posts/zero-to-neuron-series-9-vision-transformer-by-hand-every-number-every-matrix-every-why/6a02c8cb937b84f7791cad07)

### [Zero to Neuron Series 8: The Goldilocks Dilemma—Overfitting, Underfitting, and Tuning](https://importarun-dl.hashnode.dev/zero-to-neuron-series-8-the-goldilocks-dilemmaoverfitting-underfitting-and-tuning?utm_source=hashnode&utm_medium=feed)

Learn to visually diagnose Overfitting, master 4 types of Cross-Validation, and tune Hyperparameters using Python and sk-Learn in this step-by-step guide

7 min read · [importarun-dl.hashnode.dev](https://importarun-dl.hashnode.dev/zero-to-neuron-series-8-the-goldilocks-dilemmaoverfitting-underfitting-and-tuning?utm_source=hashnode&utm_medium=feed)

[Feb 15](https://hashnode.com/posts/zero-to-neuron-series-8-the-goldilocks-dilemmaoverfitting-underfitting-and-tuning/69920683d12a52d5f51589ef)

### [Zero to Neuron Series 7: Evaluation Metrics in Machine Learning: The Ultimate Guide](https://importarun-dl.hashnode.dev/evaluation-metrics-in-machine-learning-the-ultimate-guide?utm_source=hashnode&utm_medium=feed)

Master Regression, Classification, and Clustering metrics (MAE, RMSE, F1, AUC, Silhouette) with Python code, formulas, and visualizations.

9 min read · [importarun-dl.hashnode.dev](https://importarun-dl.hashnode.dev/evaluation-metrics-in-machine-learning-the-ultimate-guide?utm_source=hashnode&utm_medium=feed)

[Feb 15](https://hashnode.com/posts/evaluation-metrics-in-machine-learning-the-ultimate-guide/6991f01d7399e58021701482)

### [Zero to Neuron Series 6: Coding QLoRA - Fine-Tuning an LLM on a Single GPU](https://importarun-dl.hashnode.dev/zero-to-neuron-series-6-coding-qlora-fine-tuning-an-llm-on-a-single-gpu?utm_source=hashnode&utm_medium=feed)

We've done the analogies. We've done the math by hand. Now, it's time to make the GPU sweat. Welcome to the most practical post in the series! We're going to take all that theory from Series 4 and 5 and turn it into working Python code. Our goal: To ...

11 min read · [importarun-dl.hashnode.dev](https://importarun-dl.hashnode.dev/zero-to-neuron-series-6-coding-qlora-fine-tuning-an-llm-on-a-single-gpu?utm_source=hashnode&utm_medium=feed)

[Nov 1, 2025](https://hashnode.com/posts/zero-to-neuron-series-6-coding-qlora-fine-tuning-an-llm-on-a-single-gpu/6905d25f579c1f82cd161ab0)

### [Zero to Neuron Series 5: QLoRA By Hand — A Step-by-Step Numerical Walkthrough](https://importarun-dl.hashnode.dev/series-5-qlora-by-hand-a-step-by-step-numerical-walkthrough?utm_source=hashnode&utm_medium=feed)

Learn the concepts behind fine-tuning large language models. This post simply explains step by step math calculations behind the hood.

8 min read · [importarun-dl.hashnode.dev](https://importarun-dl.hashnode.dev/series-5-qlora-by-hand-a-step-by-step-numerical-walkthrough?utm_source=hashnode&utm_medium=feed)

[Nov 1, 2025](https://hashnode.com/posts/series-5-qlora-by-hand-a-step-by-step-numerical-walkthrough/6905b2ac7d0cce9aef9d2e59)