Conquer the LawnBuilding things. Battling photosynthesis.
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I’m looking for a new role!

I’m David Ellis

Software engineer & maker.

I’m a software engineer in San Antonio, Texas. I’ve spent 20 years building software across backend, frontend, and infrastructure at Loop Returns, Shopify, PagerDuty, and Rackspace. I’d love to bring that experience to your team.

This is where I share what I’m building and what I’m learning: programming languages, custom hardware, interactive lessons, and the occasional historical rabbit hole.

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GitHub

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Try a fuzzy search, take a programming lesson, or explore the hardware designs in your browser.

Selected projects

All 12 projects

Languages & parsers

Able

An experimental language, from its syntax and type system to interpreters and a JVM compiler.

Technologies: Go · Tree-sitter · JVM · GraalVM

Able example

struct Circle { radius: f64 }
struct Rectangle { width: f64, height: f64 }
union Shape = Circle | Rectangle

fn area(shape: Shape) -> f64 {
  shape match {
    case Circle { radius } => 3.14159 * radius * radius,
    case Rectangle { width, height } => width * height,
  }
}

Hardware

TKL Keyboard

A custom 86-key low-profile keyboard, designed across the PCB, switch fit, enclosure, and backlighting.

Technologies: KiCad · PCB design · CAD · ZMK

Education

Programming Crash Course

An interactive programming course in Python, JavaScript, TypeScript, and Ruby, with a REPL alongside the lessons.

Technologies: Vue · TypeScript · WebAssembly

History & research

Bible Timeline

A chronology search engine that makes calendar choices, interpretive assumptions, and timing constraints explicit.

Technologies: Crystal · Constraint solving · CSPICE

Hardware

Autonomous Chessboard

A physical chessboard design with magnetic piece movement, collision-aware planning, and an interactive assembly simulator.

Technologies: Python · OpenSCAD · CoreXY · Three.js

From the blog

All posts

Modular Monoliths

I just ran across a pretty good series of posts on modular monoliths: Modular Monolith: A Primer - Kamil Grzybek What is a Modular Monolith architecture - introductory post in…