Hi, I'm

Vinicius.

I build systems that need to be right.

Senior full-stack engineer. Ruby on Rails, data-intensive systems, backend performance, legacy modernization, and applied AI, from ML pipelines to LLM-powered products.

• You don't understand Machine Learning until you implement it from scratch

  Calling sklearn.fit() isn't understanding. Building a perceptron, logistic regression and a net that solves XOR in Ruby is. ML is algebra and optimization — not magic.

  2026-07-30

• Gradient descent, visually explained

  Cost function is a surface. Derivative is slope. θ = θ − α·∇J(θ). Every neural net you've ever heard of is this rule, repeated.

  2026-07-23

• epoll and io_uring, explained visually

  Blocking IO → select → poll → epoll → io_uring. Every step exists because the previous one stalled. Async isn't a language feature, it's a kernel feature.

  2026-07-16

• How the Linux kernel actually receives an HTTP request

  NIC → driver → IRQ → softirq → IP → TCP → socket buffer → accept queue → Puma. Your framework is the last 5% of the request. The rest is kernel.

  2026-07-09

• The "exactly once" myth

  Exactly-once doesn't exist on the network. What exists is at-least-once plus idempotency. Stop chasing a marketing myth — design for reality and sleep at night.

  2026-07-02