1. A computer implemented method for dynamically assembling a topology tree of a portal page, comprising: loading an existing topology tree of a portal page from storage, wherein the existing topology tree comprises a plurality of nodes; marking a node of the plurality of nodes of the existing topology tree a dynamic node, wherein said dynamic node comprises a node of said plurality of nodes that references a fragment placeholder, and wherein said fragment placeholder comprises a node that is to be resolved at runtime; assigning, by a dynamic assembly module, an adapter to said dynamic node; creating, using said adapter, a topology tree fragment, wherein said topology tree fragment comprises a partial topology tree that is built at runtime; and replacing, by said dynamic assembly module, said fragment placeholder with said topology tree fragment at runtime; assigning an expiry time to topology fragment, wherein the topology fragment does not change for a given period of time, wherein replacing, by said dynamic assembly module, said fragment placeholder with said topology fragment at runtime, comprises: replacing, by said dynamic Assembly Module fragment, said fragment placeholder at runtime if said expiry time is not expired.