Just Is Just Great

Feb 27, 2026

Addison Emig

Lead Software Engineer

The Problem

We work on software projects across a variety of programming languages and build systems. Some of them provide an easy way to run development commands (for example, npm run), and others do not.

You need some way to answer the questions “How do I set this up?” and “How do I run this?”. You need some form of documentation of common commands.

It’s easy to write this documentation once and then forget to update it as your project grows.

We needed a system that we can use on any project, no matter the language or build system. Something that would keep the development commands and related documentation in sync.

Why `just` is great

just is just great because it solves several problems at once while keeping things simple. You only need one simple file and one simple command. just is a command runner that reads all your common project commands (called recipes) from a single file. You can also add explanation comments above each recipe and just will automatically include them in the help output.

Our core recipes

For any of our active projects, a new developer can run just to get a list of the available recipes. Our core set of recipes includes:

default - to list recipes
deps - to install dependencies
setup - to run all required commands to set up a local development environment

just automatically runs the first recipe of your file if you run just without any arguments. We take advantage of this by always putting the default recipe at the top, and have it list the available recipes with just --list.

Many of our projects also have a test recipe for running the automated test suite. You’ll also often see at least one of dev, up, run-mobile, or run-docs for running the given project in the local development environment. We use lint and format recipes to trigger the correct linter and formatter for the project’s programming language.

A quick example

Here is a minimal example that demonstrates all of our core recipes, along with a dev recipe. This is actually the current justfile from our docs-template repository.

# List available recipes
default:
    @just --list

# Install dependencies
deps:
    npm i

# Set up development environment
setup: deps
    pre-commit install

# Run in development environment
dev:
    npm run dev

The comments above each recipe are automatically included in the output of just --list:

Available recipes:
    default # List available recipes
    deps    # Install dependencies
    dev     # Run in development environment
    setup   # Set up development environment

Why we’re adding a `justfile` to each of our active projects

Having a justfile in every active project means that new developers can get started quickly in a project they’ve never worked in before. The “muscle memory” of just to list available recipes and just setup to set up the local environment makes things very convenient.

We can onboard developers to projects quicker, and we can spend more time focused on writing code rather than internal developer documentation.