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Aleksei Aleinikov
Aleksei Aleinikov

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๐Ÿง  How a Deep Learning Framework Actually Works (From-Scratch PyTorch Clone)

What happens under the hood when you call .backward() in PyTorch?
Spoiler: itโ€™s way more magical โ€” and mechanical โ€” than you think.

In my latest post, I walk through building a mini deep learning framework from scratch, inspired by PyTorch.
Youโ€™ll learn:

  • ๐Ÿ“ฆ How tensors are really stored (hint: it's all flat memory)
  • โ†”๏ธ How slicing, transposing & reshaping work without copying data
  • ๐Ÿงฎ What broadcasting actually does โ€” and how it impacts gradients
  • ๐Ÿ” The magic behind autograd & computational graphs
  • โš™๏ธ Key optimizations: block matrix multiplication, in-place ops, memory reuse

๐Ÿ‘‰ Read the full deep dive here (code examples included):
๐Ÿ”— How a Modern Deep Learning Framework Works: Insights from Building a โ€œPyTorch-Likeโ€ Library from Scratch

๐Ÿง‘โ€๐Ÿ”ฌ Whether youโ€™re building custom layers, debugging weird gradients, or just curious how deep learning actually works โ€” this will make you a better ML engineer.
Even if you never touch C++ or CUDA, understanding tensor internals helps you:

  • Avoid shape mismatch headaches
  • Optimize memory & performance
  • Write cleaner, faster, more reliable training code

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