distance_of_time_in_words is a small Ruby gem that turns two Time objects into a human-readable string like “3 days and 4 hours”. Two separate bug reports against it this year turned out to be variations on the same theme: computing a duration between two timestamps is not the trivial subtraction it...

My previous post walked through four bugs in ruby-enum, a gem I maintain, all stemming from the fact that class-level instance variables aren’t inherited by subclasses. The third fix, #59, made keys, key?, value?, key, value, to_h, parse and each walk up superclass and merge in a parent’s enums, so ...

The ruby-enum gem is a small library I maintain that adds enum-like behavior to a class via include Ruby::Enum and define :KEY, value. Four pull requests landed against it recently, each fixing a different symptom, and all four turned out to be the same underlying bug: class-level instance variables...

The slack-ruby-client library, an open source Ruby gem I maintain, runs a scheduled GitHub Actions workflow that regenerates code from Slack’s API definitions and opens a pull request with the diff. The commit message and CHANGELOG entry used to be a generic “Update API (2026-08-11)”, which told a r...

AI-first Engineering is now the operating default in many organizations, including mine. Developers have kept up. Vibe coding became agentic engineering, and the race towards truly autonomous engineering isn’t slowing. But what are we, managers, to do? A manager job continues to include recruiting a...

In April 2025 I wrote Apologizing for My Obsessiveness Over Punctuation, a post about my various organizational compulsions. Near the end, almost as an aside, I mentioned that I obsessively categorize expenses in Monarch, a personal finance app, linking it with my referral code. That post earned me ...

Before AI coding assistants, a typical engineering team built expertise with the years: new team members joined, contributed small bug fixes, then were given more ambitious tasks over time as they became more comfortable in a codebase, to ultimately become experts. This process took years. In contra...

Yesterday I described AI-generated code as “plausible-looking, locally coherent, globally wrong.” Here’s a concrete example from my own codebase. I needed a cleanup job to close old Slack group DM conversations in my slack-sup2 app. The AI-generated solution looked perfectly reasonable: def close_ol...

Before AI coding assistants, a typical engineering team of 8-10 people might have been lucky to have one or two “10x engineers”, or “workhorses”, the kind of engineer that both keeps project quality and feature velocity high. AI tools have solved the workhorse half of this equation, enabling massive...

In today’s shocker, Meta is to “create a new applied AI engineering organization aiming for an ultra-flat structure of up to 50 employees to one manager”. Like all software engineers I, too, tend to apply a data‑driven, mathematical approach to every problem in the world. Yet I would have chosen a m...

Dries Buytaert recently wrote about The Third Audience. For decades, websites have targeted two audiences: humans and search engines. AI agents are now the third audience, and most websites aren’t optimized for them yet. AI agents prefer clean, structured content over HTML. Markdown is ideal - it’s ...

I’ve written and talked extensively about Hypermedia APIs for about a decade. The HATEOAS constraints in representing resources for a RESTful API has numerous advantages in API design, readability, discoverability, and performance over a hand-rolled REST API. Unfortunately, adoption of Hypermedia AP...

One of the negative side effects of having any top-down command structure is that every additional layer risks introducing a new level of bureaucracy, which then actively subtracts value. Consider the Politburo of the USSR with dozens of offices of skilled bureaucrats. Because most produced no actua...

The most abused principle in dysfunctional organizations is “Disagree and Commit”. In Don’t Tell Engineers What to Do I said that “telling people what to do, especially if they are in your direct reporting chain, must not be mistaken for “Disagree and Commit”. So, what is a healthy “Disagree and Com...

A famous example where telling Engineers what to do backfired was the Space Shuttle Challenger disaster in 1986. Engineers at Morton Thiokol, the contractor responsible for the shuttle’s solid rocket boosters, warned NASA management that the O-rings in the boosters could fail in cold weather. The ni...

Let’s get Claude Code to connect to Google Sheets. We’ll use this Google Sample Spreadsheet. Go to the Google Cloud Console, create a new project, and enable the Google Sheets API on it. Install the Google Cloud CLI. brew install google-cloud-sdk Choose the newly created project on the command line....

Six months ago I failed a basic coding interview at a FAANG. Yes, I was a Principal Engineer, and yes, I was paid absurd amounts of money, yet I couldn’t implement a diameter of a binary tree as a “warm up” exercise, 10 lines of code. The interviewer was very nice about it, and was equally surprised...

One of my colleagues wrote a pretty awesome tool called claude-swarm that orchestrates multiple Claude Code instances as a collaborative AI development team. At Shopify, we are attempting to use it to generate Ruby unit tests at some scale with an army of AI test agents (think a “Ruby Expert” paired...

There’s much written about becoming a first time Engineering Manager (I recommend Camille’s book), but little about the second time. To my own surprise, I am back to being a manager after almost 6 years of writing code as an individual contributor (IC). Two months ago I joined the Developer Producti...

Last week, my team at Shopify released a new tool called Roast, a convention-oriented framework for creating structured AI workflows. Our vision is to enable A.I. agents to solve developer productivity problems at scale. Imagine continuously improving unit tests, or optimizing test performance acros...

You may have landed here because I had just apologized for my obsessiveness over punctuation in a GitHub comment and requested changes to your pull request, or you noticed me adding periods to a sentence in the otherwise excellent document you have authored. This is not the first time, and my condit...

Friday, February 14th is my last day at Amazon. I’ve been at Amazon for over 5½ half years, and it’s been a great run. I came from 8 years of leading technology at Artsy, and wanted to go back to coding. I found a Principal Engineer role to help launch the new AWS Data Exchange service. I was excite...

Should you work on week-ends? tl;dr Only 2% of my paid work was accomplished on weekends, which matches my opinion that you should not. Collecting Data First, let’s try to use data and find out whether I actually work on week-ends. I’ve contributed to the open-source OpenSearch since 2021 as part of...

Most paying customers expect a certain level of (paid) support. One opens a ticket, gets a response, and any issue can be resolved. How does “support” work in open-source? My rule of thumb is to meet users where they are. GitHub projects have issues, but opening an issue to ask a question is general...

I found it annoyingly non-trivial to add a spell checker to this blog. For now, I settled on GitHub Spellcheck Action that uses PySpelling on files changed in the commit or pull request as described in this blog post. name: Check Spelling on: [push, pull_request] jobs: check: runs-on: ubuntu-latest ...

Since my first day in AWS 5 1/2 years ago, I’ve been experimenting with keeping a CHANGELOG of everything I do, available for everyone at the company to see. I wrote about it here. If you work at AWS, use the URL in the screenshot below to find it. I wrote a little script to try and classify where I...

Have you watched The IT Crowd? It’s a hilarious British television sitcom from around 2006 that cast a bunch of IT geniuses at the Reynholm Industries tech support department in London. One of the signature laughs is that every time the phone rang, Roy would pick it up and without waiting say “Have ...