Web portal application customization methods and systems using profiles allow developers to expose different functionalities and a different look and feel to users belonging to different user profiles. Specifically, the method allows a developer to define default and profile-specific transitions as well as default and profile-specific states. Upon request of a transition by a workflow engine, the system transparently provides the workflow engine with a profile-specific transition if a profile-specific transition associated with the user is available. If a profile-specific transition is not available, the system provides the application with a default transition. Likewise, the system transparently provides the application with a profile-relevant state according to the profile of the user and the availability of a profile-specific state. Accordingly, the method may implement highly customizable functionalities and look and feel effectively and cost-efficiently.