Office 365 provides a rich set of services from Exchange online, SharePoint online, the Office Graph, and more. Satya Nadella says this is Microsoft's "most important developer surface area," and for good reason: it's where users put a lot of their most important business information! In this talk you’ll learn how to follow the patterns Microsoft uses in its NextGen portals to build your own modern applications that incorporate Office 365 services along with data from line of business systems. You’ll learn to build mobile-ready, responsive web sites that are unencumbered by the SharePoint UI and that run directly from the Office 365 application launcher. These solutions provide single sign-on with Azure Active Directory; you'll learn how to do this from an ASP.NET MVC application and from AngularJS. Come learn how to have the best of both worlds by building a Next Generation portal of your own!