Build a Deep Learning Library

Forget downloading yet another AI toolkit — this free online book says build your own. Starting with a blank file and NumPy (a popular math toolbox), it walks you to a “teach-your-code-to-learn” engine and simple layers, then trains handwritten digits (MNIST) and baby versions of image models. It’s free, with pay‑what‑you‑want on Gumroad, and there’s even an email for feedback. The crowd showed up with soldering irons and receipts: amitav1 flexed a C++ attempt to build a whole chatbot brain, sharing a repo; csantini chimed in that DIY is the best way to learn, linking claudioflow; grandimam cheered it as perfect for software engineers fed up with black boxes.

Then came the spice. yunnpp waved the C flag: NumPy is comfy, but real understanding means wrestling pointers, not pillows. Others shot back that NumPy keeps the math honest, and beginners shouldn’t get lost in memory gymnastics. silentsea90 asked if this is basically Karpathy’s “Zero to Hero” — cue the meme wars of “Karpathy approved” vs “we were doing this before it was cool.” Jokes flew: “DIY or die,” “I, for one, welcome our C overlords,” and “autograd is just your code doing its own homework.” Beginners cheered, purists sharpened their knives