This talk is about how my company took a broken e-commerce and LMS site written in an older style MVC framework and re-wrote a significant portion of it in Symfony and related tools (Doctrine, FOS Bundles, Sonata) over 6 months and created a stable, well-tested application. I’ll cover the approach we took to rewriting the admin panel in Symfony, writing an API, introducing Behat and PHPUnit tests for both new and legacy code (still in a separate framework) and setting up Continuous Integration. I’ll discuss how we optimized the site as we went, by identifying weak spots in the code and how we addressed them. I’ll also cover what we would do differently now that we’ve done it once.