User retention and sales conversion is directly impacted by a site's speed. However, enhancing the performance of a large website can be tricky, and requires a mix of art and science. In this course, learn about a variety of tools and techniques for developing high-performing PHP software. Instructor Justin Yost discusses how to think about performance optimization, measure the performance of your PHP software, test to ensure you're not losing users to a slow page load, optimize your database queries, and more.