The website appears to be related to web performance monitoring and optimization. It includes code snippets related to measuring performance using the window.performance API, as well as functions for handling errors and promises. There is also a mention of polyfills for detecting browser compatibility and improving performance. The purpose of the site may involve providing instructions or resources for developers to enhance their website's performance. However, without further context or additional information, it is difficult to provide a comprehensive summary or determine the specific focus of the website.
