JavaScript Performance in the Wild 2020 (14 minute read)
This article analyzes the top 1 million pages on the web to find out what makes the web slow. A scripted web browser was used to browse to the root page of the top 1 million domains and log render times, request counts, repaints, JavaScript errors, libraries used, and other data. The analysis provided support for several optimization tricks, such as making as few requests as possible, using HTTP2 or greater, and avoiding render blocking requests and using async where possible. JQuery is the most popular library, but the data says it significantly slows down performance.
CodeSwing (GitHub Repo)
CodeSwing is an interactive coding environment for VS Code that allows developers to have a traditional web playground directly within their highly-personalized editors. Developers can view a live preview of their web apps as they type, without compiling or bundling anything. Demos and examples are available in the repository.