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Understanding Neural Network Architecture: From Basics to Residual Connections

18 Oct 2026 (updated: 08 Sep 2026) / 31 minutes to read

Elena Daehnhardt

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TL;DR:
  • Neural networks stack layers to transform data. Deeper networks are more powerful but suffered from vanishing gradients. ResNet's residual connections (2015) solved this by adding skip connections that preserve information flow. This breakthrough enabled networks with 100+ layers and remains foundational to modern architectures.

📚 This post is part of the "Neural Network Architecture" series

Series: Neural Network Architecture (Part 2 of 9)

Previous: Part 1 — Artificial Neural Networks

This is Part 2 of the Neural Network Architecture series. We’ll build from foundational concepts to modern innovations like DeepSeek’s mHC architecture.

Introduction

Hello, dear friends! Today I want to take you on a journey through one of the most important concepts in modern AI: neural network architecture.

When people talk about AI breakthroughs, they often focus on training techniques, datasets, or compute power. But there’s another dimension that’s equally crucial: how we structure the network itself. The architecture—how layers connect, how information flows, how gradients propagate—determines what’s possible to build.

This post is the foundation for understanding modern architectural innovations. Before we can appreciate recent work like DeepSeek’s mHC architecture or other cutting-edge designs, we need to understand the building blocks they’re built upon.

I’ll assume you have basic Python knowledge and have seen neural networks before (if not, you might want to start with my earlier post on artificial neural networks). What we’re going to explore today is deeper: not just “what is a neural network?” but “how do we structure them effectively?”

By the end of this post, you’ll understand:

  • Why network depth matters and what problems it creates
  • How residual connections revolutionised deep learning
  • Why researchers continue innovating on these foundations
  • The mathematical intuition behind these architectural choices

Let’s begin.

Part 1: The Fundamental Challenge of Depth

Why We Want Deep Networks

Neural networks transform data through layers of computation. Each layer learns to recognize increasingly abstract patterns:

  • Layer 1: Simple edges and textures (in images) or basic word patterns (in text)
  • Layer 2: Combinations of edges forming simple shapes or phrase patterns
  • Layer 3: Object parts or semantic relationships
  • Layer 4+: Complete objects, concepts, or complex reasoning

The intuition is clear: more layers = more abstract reasoning = more powerful models. And empirically, this holds true—when we can successfully train them.

The vanishing-gradient problem, the ResNet revolution and practical takeaways follow below.

Part 2: The ResNet Revolution

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Part 3: Building a Complete ResNet

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Part 4: The Impact and Legacy of Residual Connections

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Part 5: Limitations and Ongoing Research

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Part 6: Practical Takeaways for Building Neural Networks

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Closing Thoughts

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About Elena

Elena, a PhD in Computer Science, simplifies AI concepts and helps you use machine learning.




Citation
Elena Daehnhardt. (2026) 'Understanding Neural Network Architecture: From Basics to Residual Connections', daehnhardt.com, 18 October 2026. Available at: https://daehnhardt.com/blog/2026/10/18/understanding-neural-network-architecture/
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