Bootstrapping a UI component library
Building — and adopting — a component library in the context of a vibrant business is no easy feat. Here are a few things we’ve learned.
At a small …
Disguise Driven Testing: Jest Mocks In Depth — Part 2
Mocks are a great way of preventing AJAX calls in tests, but they can also help you isolate side effects and impurities that can create complicated tests.
As you learned …
The Action Pattern: Clean, Obvious, Testable Code
Let’s convert a mock API endpoint for signing up new users in a mobile app into using the action pattern.
JavaScript Performance Pitfalls in V8
Benedikt shows how V8 compiles your JavaScript programs, and explains a few tricks you can use to avoid draining application performance down the sink.

Okta, Auth0, & the Goblet of Identity
I’ve been exploring a couple of different options when it comes to serverless authentication providers, and I was both pleased and surprised to find how little …
16m 1
A Guide to Modular Design Thinking
Last year I gave a presentation about Modular Design and here’s a transcript.
29m 4
An Introduction to Speculative Optimization in V8
An impressively low-level article that we hope gives you a good idea about what happens in V8 when it comes to optimization.
24m 4
Mastering Modular JavaScript
My latest book, Mastering Modular JavaScript, just went into Early Release and is available now on Safari Books Online. It’s a part of my “Modular JavaScript” effort. It covers module thinking, patterns & principles.
a minute 7
A Brief History of Modularity
When it comes to JavaScript, modularity is a modern concept. In this article we’ll quickly revisit and summarize the milestones in how modularity evolved in the …
9m 3
A Tiny Story about Systems Complexity
A human decides to open a new tab in their favorite web browser and they then google for “cat in a pickle gifs”. What happens next will shock you!
3m 2
Make All Images on Your Website Responsive in 3 Easy Steps
Images are crucial to website performance, but most sites still don’t implement responsive images. Cloudinary provides an alternative to
srcset
andsizes
when implementing responsive images.5m 8
Investigating Performance of Object#toString in ES2015
We discuss how
Object#toString
performs in the V8 engine, why it’s important, how it changed with ES2015 symbols, and how to speed it up.12m 1
Interviewed at Tencent Frontend Conference
Last month, I was interviewed after delivering a presentation on ECMAScript to an audience in Shenzhen, China. I think it was an entertaining interview, so here’s a transcript.
6m 0
Null Propagation Operator in JavaScript
There’s a proposal in stage 1 for the Null Propagation operator. In this article we’ll take a look at the proposal, which offers an alternative to null …
5m 25
Pattern Matching in ECMAScript
There’s a stage 0 proposal for pattern matching in JavaScript. In this article we’ll take a look at what the proposal entails and also show how you might …
9m 17
Setting up 2FA for Node.js Applications
Let’s take a look at how we can quickly hash out a correct two-factor authentication (2FA) solution for our web applications. First off, let’s work out the …
12m 2
TC39, ECMAScript, and the Future of JavaScript
Last week, I gave a presentation at Tencent Frontend Conference in Shenzhen, China. For this article, I’ve adapted its transcript.
27m 10
Regular Expressions in a post-ES6 world
In this article we’ll take a look at regular expressions improvements in and after ES6. We’ll discuss the
/y
,/u
, and/s
flags, named capture groups, unicode property escapes, lookbehind assertions, andString#matchAll
.23m 7
Mixing Generators Into Iterators
As it turns out, iterators can be written using generators. This can lead to some interesting use cases.
5m 6
Observables Proposal for ECMAScript!
There’s an ECMAScript proposal for Observables in the works. In this article we explore the proposal, the API, and look at a few use cases.
Observables in …
6m 11
Variables declared using
const
are not immutableUsing
const
only means that the variable will always have a reference to the same object or primitive value, because that reference can’t change.2m 5
Content-Security-Policy
in Express appsThe
Content-Security-Policy
header is a bit frightening — will I break my website if I suddenly start blocking requests for external resources? In this article we go over a gradual approach to adopting CSP.16m 3
Setting up an Angular 2 Development Environment
Angular 2 is the rave of the moment. It is a modern JavaScript framework that is supercharged with awesome features. In fact, Angular 2 is now more than a framework, it …
25m 8
The JavaScript Standard
JavaScript has gone from being a marketing ploy to gain a tactical advantage, to becoming the core programming experience in the world’s most widely used application runtime platform. Where to, next?
11m 3
Let’s use
const
! Here’s why.When reading a piece of code, others can take cues from these signals in order to better understand what we did. ES6 offers
let
andconst
as new flavors of variable declaration, are they better signals thanvar
?10m 21
How Terrible Code Gets Written by Perfectly Sane People
Help your team avoid some bad habits that can drive good teams to write terrible code.
8m 5
Fourth Year in Review
Another year, another review of how Pony Foo did in its latest twelve months online!
6m 1
Thousands of Color-coded Visualizations in React
For the past few days I’ve been working on a data visualization that displays Elasticsearch node distribution across different cloud instances and zones.
19m 2
Making Time for Side Projects: A Daily Habit
With so many other commitments to deal with, it can be hard to find time to work on side projects. In this article, I discuss the need for carving out a chunk of time to …
2m 5
Announcing Practical Modern JavaScript
— and the Modular JavaScript Book Series!Practical Modern JavaScript is the first book in a
series I’m dubbing Modular JavaScript, which aims to be a comprehensive, freely available, and open set of books with the mission of improving our collective understanding of modular JavaScript.
19m 2
Modular JavaScript launches in a week!
Modular JavaScript is an open effort to improve our collective understanding of writing robust, well-tested & modular applications. It is launching very soon.
6m 0
Fixing an XSS vulnerability in
marked
Earlier this year my team at Snyk added an interesting Cross-Site Scripting (XSS) vulnerability to our database, in the popular marked package. The vulnerability is …
8m 4