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From an apprentice to a master of JavaScript

Welcome to I (Juho Vepsäläinen) have gathered material related to JavaScript since 2016. You can consider this site as a learning resource at different levels where I have gathered my learnings about the topic. Given JavaScript is a broad subject, I have divided the site as follows:

Most of the content is freely available although you can support my efforts by buying books or considering some form of consulting. I work mainly around TypeScript, tooling, and web performance these days. Through my research efforts I have had to delve into the latest rendering techniques and upcoming themes like edge computing.

This site has been built using Gustwind, my personal framework that is close to HTML with an API familiar to users of React. You could consider the site itself as a learning resource as I have built it using Tailwind syntax and you can copy/paste from the source easily although my custom components have been removed from the output although you can find the custom components at GitHub.


In this book, I go through main features of webpack, a module bundler for JavaScript, and show how to compose your own configuration effectively. It doubles as a reference for common webpack techniques and I have included discussion considering alternatives. The book matches the current version of webpack.

In this book co-authored with Artem Sapegin, I explore how to maintain and publish your JavaScript projects. Originally it was split off from the webpack book. The book is largely complete although I want to give it modernization pass to catch up with the latest developments in the space.

React book is where it all started and the webpack book was split up from this. The book is not up to date although it may be interesting to follow the book project while building it using some other technology or the latest React APIs. In other words the book could use an update and it is maintained on the site for historical purposes for now.

Latest blog posts

In this post, I will introduce you to the concept of the pyramid of doom. Although the pattern is not typical anymore, it is good to know how you migh…
If you have used this site earlier, you might have noticed it looks different now. That is because I did a massive rewrite of it. I had the following …
In terms of development productivity, Continuous Integration (CI) has become a common technique across development teams across the world. In this ar…


Qwik is a recent web framework that approaches web application from a different angle by eschewing the concept of hydration and replacing it with resumability. This means it provides unique benefits, such as automatic code-splitting, out of the box making it an interesting alternative for web developers that want to develop performant websites and applications out of the box.

Deno is the followup project of Ryan Dahl, the original author of Node.js. In Deno, Ryan wanted to fix his perceived mistakes of Node.js and Deno could be characterized as a whole toolbox that comes with solutions for common server-side programming problems particularly in terms of tooling.

Web Audio is a powerful, yet underestimated, web API that allows you to build complex audio-based web application. In this kata, you will build a small Digital Audio Workstation (DAW) while getting acquainted with the relevant APIs and some of the history behind digital audio.