Asynchronous JavaScript: Async/Await Tutorial
Asynchronous JS with async/await is easier to teach than Promises and yields even cleaner looking code. Most modern browsers already have support, but with Babel or another transpiler, you can get up and running quickly.

SQL Keys in Depth
This is probably more than you ever wanted to know about keys in SQL. The article focuses on PostgreSQL but the information is fairly transferable to other SQL technologies.

Finding Dead CSS
This is a handy quick hack to help determine if some CSS is dead and no longer needed. It may not be as effective if you have a large application with low traffic where every part of the application isn’t visited regularly. If you are needing to test multiple rules at a time I’d suggest adding query parameters if your logging displays them.

Confused about the different types of dependencies in NPM or Yarn?
The kind of dependencies you use in NPM and Yarn matters. This diagram compares dependencies to things around your home, making it easy to understand.

Free Programming Books
This site has a collection of high-quality PDF ebooks on various topics. The algorithms ebook looks a bit like a slimmed down version of my college book, with a bit less theory involved.

React.Fragment and Semantic HTML
React can be very easy to use, but if you’ve ever looked at the HTML it yields you know things can get messy. Fragments should help with that by acting as a non-rendering container element. With it, you won’t end up with a bunch of divs strewn throughout your code only for the sake of React.