There exist many portal servers that support the construction of portals that is portals that allow the user to have one or more personal pages composed of a number of personalizable services. The main drawback of current portal servers is their lack of generality and adaptability. This paper presents the design of MyPersonalizer a J2EE-based framework for engineering My portals. The framework is structured according to the Model-View-Controller and Layers architectural patterns providing generic adaptable model and controller layers that implement the typical use cases of a My portal. MyPersonalizer allows for a good separation of roles in the development team: graphical designers (without programming skills) develop the portal view by writing JSP pages while software engineers implement service plugins and specify framework configuration.