Thomas Countz

I recently hacked together an ESP-01 and a cheap solar garden lantern1 so that I can have warm flickering candlelight whenever the mood strikes.

Good Citizen Syndrome is what happens when engineering leaders—often unwittingly—confuse good reliable engineers with good reliability engineering.

I was recently asked the question: “Can we just use ActiveJob instead of Kafka?”

This is Unsafe If you type thisisunsafe on a Chrome SSL error page, Chrome will bypass the error and load the page for you.

Debounce Delay: 500ms Hardware The term “debouncing” originates from electronics (at least that’s where I first came across it).

Much like having thoughts in the shower and working on trains, I often find my best thinking happens while walking my dog in the morning.

Inspired by Andreas Wagner’s ecr word, I created the word go: \ go.fs : go#empty s" ---marker--- marker ---marker---" evaluate ; : go#open s" vim my_project.fs" system ; : go#run s" my_project.fs" included ; : go go#empty go#open go#run ; marker…

module Colors refine String do def red = "\e[31m#{self}\e[0m" def green = "\e[32m#{self}\e[0m" def yellow = "\e[33m#{self}\e[0m" def blue = "\e[34m#{self}\e[0m" def magenta = "\e[35m#{self}\e[0m" def cyan = "\e[36m#{self}\e[0m"

Every so often, I like to write a Ruby script that says good morning to my team in a fun way.

I use entr to run commands automatically when files change.

tl;dr Numbered block params (_1, _2, etc.) are reserved and read-only, while it (the new block param in Ruby 3.4) has different mutation rules for compatibility.

In A Life-Saving Checklist, author Atul Gawande describes a patient suffering from an infection introduced by medical equipment.

I built an interactive tool for visualizing task progress.

When you’re interested in testing the actual SQL queries generated by ActiveRecord, rather than just what’s returned from the database, you can capture them using ActiveSupport::Notifications. module QueryCapturing IGNORED_QUERIES = ["SCHEMA", "TRANSACT…

def print_progress(title, total, current_progress, bar_width: 50) progress_pct = (current_progress.to_f / total) * bar_width printf("\r#{title}: [%-#{bar_width}s ] -- %s", "▤" * progress_pct.round, "#{current_progress}/#{total} ") end # Usage 1.upto(…

I’ve been playing around with the idea of building a checklist app that’s geared towards completing procedures.

I built an interactive jq TUI using fzf!

Turn your ApplicationRecord models into a Mermaid ERD Rails.application.eager_load!

Update 2026-01-04 After trying this out for a while, I’ve found that I added a new, potentially worse, friction: having to ask myself “…is this worth a blog post or should it just be a ‘journal’ entry?”

Inspired by biological systems, evolutionary algorithms model the patterns of multi-generational evolution in order to unearth unique ideas.

One of the tasks we often find ourselves completing on Zendesk’s Core Ruby Engineering team is helping to keep a variety of projects up to date.

tl;dr Do a thing you already know how to do.

Dataset retrieved from: Utrecht University & Google, 2021, via Google Environmental Insights Explorer (August 2021) The Jupyter notebook used to do this analysis is available here as a Binder and here as a Gist for you to explore!

You’re on Ops.

The Anomaly Early today, Rocket Lab launched their 20th Electron rocket, Running out of Toes from their Launch Complex 1 Mahia Peninsula in New Zealand.

Pictured above is a printed circuit board or PCB.

Pictured above is the schematic for Hexo’s circuit.

Good communication in an emergency is vital: What is happening?

Foreshadowing: signaling an outcome of chapter eight in the middle of chapter one, i.e. the original spoiler.

In The Design of Everyday Things, Don Norman shares an anecdote about “signifiers,” which are the design elements that communicate the purpose, structure, and operation of an object or system.

Arduino has a built-in tone() library which allows you to send a PWM frequency at 50% duty cycle to a specific pin in order to generate a tone on a piezoelectric buzzer with an optional duration. tone(pin, frequency) tone(pin, frequency, duration) This f…

An SQL Injection occurs when untrusted input is used directly in the construction of an SQL query.

Originally published on 8th Light’s blog As I sit down to write, I noticed a tug at the back of my neck—a tension forming as I begin editing my words obsessively.

If you’re like me, you may have versions of both Bundler 1 and Bundler 2 installed on your system.

Earlier this week, my pair and I struck upon something interesting, and I stopped to take notes.

Fastai, known for it’s MOOCs, is working on a book, Fastbook to go along with their new MOOC starting July 2020.