# Gustavo Widman's Blog

> A collection of articles on systems programming, NixOS infrastructure, and cybersecurity research.
> URL: https://guswid.com/blog
> Generated: 2026-04-06T09:54:23.926Z

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## Available Posts

Currently, there are 11 posts available. Each post includes the title, publication date, tags, an excerpt, and a link to the full markdown content.

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### [http from scratch, on top of a homemade tcp stack, in rust](https://guswid.com/blog/http-impl.mdx)

> Date: 2026-04-06
> Tags: rust, networking, http, tcp, tun, systems-programming, cross-platform

i had a working tcp stack. the logical next step was to parse http by hand. this is how that went.

[read full article](https://guswid.com/blog/http-impl.mdx)

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### [a billion rows later](https://guswid.com/blog/1brc.mdx)

> Date: 2026-03-30
> Tags: rust, performance, simd, optimization, 1brc

how a college assignment turned into a performance rabbit hole

[read full article](https://guswid.com/blog/1brc.mdx)

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### [tcp from scratch, over a tun device, in rust](https://guswid.com/blog/tcp-impl.mdx)

> Date: 2026-03-23
> Tags: rust, networking, tcp, tun, systems-programming, cross-platform

i built a tcp stack without touching the socket api once. this is how it went, including the three bugs that almost made me quit.

[read full article](https://guswid.com/blog/tcp-impl.mdx)

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### [homemade udp in rust](https://guswid.com/blog/udp-impl.mdx)

> Date: 2026-03-16
> Tags: rust, networking, udp, raw-sockets, systems-programming, college

college said "implement udp from scratch." i said "can i use rust?" it spiraled from there.

[read full article](https://guswid.com/blog/udp-impl.mdx)

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### [teaching rocks to fix themselves with hamming codes](https://guswid.com/blog/hamming-rust.mdx)

> Date: 2026-03-09
> Tags: rust, networking, algorithms, bit-manipulation

i overengineered a university assignment in rust to understand how computers magically correct their own errors at the bit level.

[read full article](https://guswid.com/blog/hamming-rust.mdx)

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### [overengineering the 'rinha de backend' with rust and sqlite](https://guswid.com/blog/rinha-de-backend.mdx)

> Date: 2026-03-05
> Tags: rust, hpc, backend, database, optimization

how i squeezed ~2900 rps out of a tiny rust api by dropping postgres and pushing sqlite to its limits.

[read full article](https://guswid.com/blog/rinha-de-backend.mdx)

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### [getting rust to run on bare metal without hacks](https://guswid.com/blog/based-kernel.mdx)

> Date: 2026-03-04
> Tags: rust, osdev, assembly, x86-64, bootloader

when a simple homework assignment spirals into writing raw assembly to flip cpu registers.

[read full article](https://guswid.com/blog/based-kernel.mdx)

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### [modernizing rsync for the multi-gigabit era](https://guswid.com/blog/modernizing-rsync.mdx)

> Date: 2026-03-02
> Tags: rust, systems-programming, optimization, thesis, rsync

a thesis on why rsync's 1996 algorithm is cpu-bound on modern networks and how hardware optimizations might finally unlock our bandwidth.

[read full article](https://guswid.com/blog/modernizing-rsync.mdx)

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### [escaping dependency hell with nix](https://guswid.com/blog/nix-intro.mdx)

> Date: 2026-02-24
> Tags: nix, infrastructure, devops, nixos

i spent 7 months building a nix infrastructure so i never have to run npm install again. here's why docker is overkill and how nix works under the hood.

[read full article](https://guswid.com/blog/nix-intro.mdx)

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### [i beat pytorch with a zero-dependency rnn in rust (kind of)](https://guswid.com/blog/rnn-rust.mdx)

> Date: 2026-02-19
> Tags: rust, machine-learning, optimization, rnn, performance

how i accidentally optimized a handmade rnn to be 60x faster than pytorch on small datasets.

[read full article](https://guswid.com/blog/rnn-rust.mdx)

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### [automating terraria fishing with rust and memory manipulation](https://guswid.com/blog/terraria-autofish.mdx)

> Date: 2026-02-12
> Tags: rust, reverse-engineering, systems-programming, game-hacking

how i went from failing with ocr to writing a performant cheat in rust using assembly pattern scanning and jit hooking.

[read full article](https://guswid.com/blog/terraria-autofish.mdx)

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## How to Access

- **Individual posts**: Append `.mdx` to any blog URL (e.g., `/blog/rnn-rust.mdx`)
- **All posts combined**: `/llms-full.txt`
- **URL parameters**: Add `?format=markdown` or `?raw=true` to any blog URL