Hi! I'm Chris. I'm a technologist living in San Francisco and co-founder of Grove Collaborative. Over the years I've written a number of articles about software, technology, and teams. I hope you'll find some of them useful.

We're Hiring!

My company, Grove Collaborative, is hiring full-stack engineers. If you like what you read here, and want to work on similar problems, email me ([email protected]) or learn more & apply.



A Simple Trending Products Recommendation Engine in Python

Our product recommendations were boring. I knew that because our customers told us. When surveyed, the #1 thing they wanted from us was better product discovery. And looking at the analytics data, I could see customers clicking through page after page of recommendations, looking for something new to buy. We ...


How to Buy Expensive Software Part 1: Vendors & Demos

Some days it seems like all I'm good for is buying other companies' software.

It's a little ridiculous. I get 5-10 emails a day pitching some SaaS solution. You probably get them too. Recognize any of these subject lines?

  • Christopher, do you have 15 minutes to connect about ...


Photography & Journalism with Darcy Padilla & Julian Cox - Opening Remarks

On November 17th, I chaired an event at the de Young Museum related to the opening of the exhibit Danny Lyon: Message to the Future. It's there through April 30th, 2017 and I encourage anyone in San Francisco during its run to see it. Danny Lyon is a remarkable ...


What does engineering do here?

My company, Grove Collaborative, is an online brand and retailer for non-toxic household consumables. We sell physical products on the internet, that get shipped from our warehouses to our customers. This is so simple that it's almost always met with some incredulity. We're a Silicon Valley startup after ...


Actually Understanding Timezones in PostgreSQL

Timezones are the worst. We should all just live in UTC, reasonable sunset hours be damned. And learning about timezone implementation details is incredibly boring and esoteric1, so most developers are not inclined to figure out what the hell is actually going on until they really need to. Like ...


Eight Surprises During My First Year as a Father

I have a 13-month-old son named Dashiell (pronounced Dash-uhl, and I'm sorry in advance to schoolage Dashiell, whose teachers will all say "Dah-sheel?" on his first day). He's awesome. I mean...I'm not super objective, but even so, he's definitely a good dude. We're going ...


Zero Downtime Rebrand

Noah Smith and I gave this presentation at the San Francisco Django meetup in March of 2016, shortly after we rebranded ePantry to Grove Collaborative. Here's how we pulled it off.


The First Thing I Tell New Engineers

The first thing I tell junior programmers is: keep going.

If you've been programming a while, you know that feeling of encountering a new project, with a new stack, in a new language. The feeling is: OK. And you roll up your sleeves and get to work.


Software at Companies that Don't Sell Software

If you're a software professional, there are two types of companies you might work for; those whose products are fundamentally software (they make money directly from technology), and those that make their money some other way, but rely on software. Let's call the first Type A, and the ...


Trello vs. Asana

In two totally different companies over the past 4 years, across different personalities, teams, and processes, I've seen Asana rejected no fewer than a dozen times in favor of Trello, in spite of multiple executive mandates to use Asana.


Pushing Bits with Python

When was the last time you needed to directly manipulate a bunch of binary data? Most engineers run across it only in the context of bit flags and masks in C++ or Java.

It's a little rarer to muck about with direct binary file data. It's nonetheless quite ...


A Simple Content-Based Recommendation Engine in Python

Let's pretend we need to build a recommendation engine for an eCommerce web site.

There are basically two approaches you can take: content-based and collaborative-filtering. We'll look at some pros and cons of each approach, and then we'll dig into a simple implementation (ready for deployment on ...


How Celery Chord Synchronization Works

Celery is a powerful tool for managing asynchronous tasks in Python. The basic model is synchronous Python code pushes a task (in the form of a serialized message) into a message queue (the Celery "broker", which can be a variety of technologies - Redis, RabbitMQ, Memcached, or even a database), and ...


Refactoring for Testability: A Real World Example in Python/Django

At ePantry, we strive to have enough automated test coverage that we can deploy with confidence, without being dogmatic about our approach. We certainly aren't a TDD shop, and we don't have rules about code coverage metrics ("no commit can reduce code coverage!"), but it's very unusual ...


The No-Frills Guide to PGP on OS X

Want to get started using PGP on your Mac, but confused by the morass of professor-doctor style sites with seemingly out-of-date software and plugins? Have no fear! I'll have you up and running in minutes with this handy guide. You'll learn how to use public key servers and ...