Building Neural Networks from Scratch Demystifies Deep Learning Mechanics

Yuanzhe Jia· July 21, 2026 View original

Summary

This paper introduces a self-contained neural network framework built entirely without high-level libraries or automatic differentiation. It serves as a pedagogical tool to explain fundamental deep learning concepts and demonstrates robust performance on a multi-class classification task.

Many modern deep learning frameworks abstract away the core mechanics of neural networks, creating a knowledge gap for developers. This research presents a complete neural network implementation built from the ground up, avoiding reliance on pre-built modules or automatic differentiation. The framework includes essential components like multi-layer architectures, various activation functions, regularization techniques, and advanced optimizers. It aims to clarify concepts such as forward/backward propagation, gradient dynamics, and optimization landscapes. Beyond its educational value, the framework proves its effectiveness and numerical stability on a multi-class classification task, validating its design and generalization capabilities across different configurations. Its modularity also positions it as a strong baseline for further educational and research endeavors.

Why it matters

Professionals can gain a deeper understanding of neural network internals, which is crucial for debugging, optimizing, and innovating beyond standard library usage. This foundational knowledge can lead to more effective and customized AI solutions.

How to implement this in your domain

  1. 1Study the framework's code to understand the manual implementation of core deep learning algorithms.
  2. 2Apply the principles learned to debug and optimize existing models built with high-level libraries.
  3. 3Develop custom neural network components or layers when standard libraries fall short.
  4. 4Use the framework as a teaching tool for new team members entering AI development.

Who benefits

Software DevelopmentEdTechResearch & DevelopmentAI Consulting

Key takeaways

  • Understanding neural network internals is vital despite high-level library abstraction.
  • A from-scratch implementation clarifies forward/backward propagation and optimization.
  • Such frameworks can serve as robust educational tools and research baselines.
  • Deep foundational knowledge enhances debugging and custom solution development.

Original post by Yuanzhe Jia

"arXiv:2607.16682v1 Announce Type: new Abstract: The widespread adoption of high-level deep learning libraries, while accelerating model development, has increasingly abstracted away the internal mechanics of neural networks, creating a gap between practical usage and fundamental…"

View on X

Originally posted by Yuanzhe Jia on X · view source

Want to go deeper?

Turn these trends into skills with Learnijoy's hands-on AI & tech courses.

Explore courses