VoDKA is a Video-on-Demand server developed using Erlang/OTP. In this paper, the evolution of the core architecture of the system, designed for improving resource modelling, is described. After explaining the main goals of the project, the steps taken towards an optimal architecture are explained. Finally, a new architecture is proposed, solving all the problems and limitations in the previous ones. Special attention is paid to the use of design patterns, implementation behaviours, and reusable software components.