<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"><channel><title>Vitor Sousa — Foundations</title><description>Reference explainers for ML fundamentals: math, architectures, and implementations from scratch.</description><link>https://www.vitorsousa.com/</link><image><url>https://www.vitorsousa.com/favicon.svg</url><title>Vitor Sousa — Foundations</title><link>https://www.vitorsousa.com/</link></image><item><title>Building a Transformer: The Complete Forward Pass</title><link>https://www.vitorsousa.com/foundations/building-a-transformer/</link><guid isPermaLink="true">https://www.vitorsousa.com/foundations/building-a-transformer/</guid><description>Layer normalization, residual connections, feed-forward networks, and the full decoder-only transformer assembled piece by piece with tested PyTorch code.</description><pubDate>Fri, 24 Apr 2026 19:00:00 GMT</pubDate></item><item><title>Positional Encoding: Teaching Transformers to Count</title><link>https://www.vitorsousa.com/foundations/positional-encoding/</link><guid isPermaLink="true">https://www.vitorsousa.com/foundations/positional-encoding/</guid><description>Sinusoidal, learned, and rotary position embeddings — the math of why position information is necessary and how each approach encodes it.</description><pubDate>Thu, 02 Apr 2026 19:00:00 GMT</pubDate></item><item><title>Attention Is All You Need to Implement</title><link>https://www.vitorsousa.com/foundations/attention-from-scratch/</link><guid isPermaLink="true">https://www.vitorsousa.com/foundations/attention-from-scratch/</guid><description>The complete guide to attention mechanisms — from the matrix math of scaled dot-product attention through multi-head projections to a tested PyTorch implementation. Every equation derived, every dimension explained.</description><pubDate>Wed, 01 Apr 2026 19:00:00 GMT</pubDate></item></channel></rss>