Slides of the session as part of the International PHP Conference in Munich 2014. Today's websites are rather complex applications which try to create the illusion of an homogeneous user experience. A content management system might ultimately render the markup, but shops, product information systems or booking engines deliver content, too. Which architecture and mechanisms are necessary to seamlessly integrate third party systems into a CMS? Which strategies allow you to make your website scalable and perform well? This session doesn't provide you with a one-fits-all solution but rather shows the thinking behind a typical project architecture and the pros and cons of different options. Includes examples based on TYPO3 Neos.