Monolithic rich Windows applications are not enough for our customers. We are often requested to provide a web front-end, or a REST server to be consumed by mobile or thin clients. Integrating n-Tier architecture to an existing project is challenging. Some good practices, based on industry standards and proven design patterns (like uncoupling or SOLID) can be mind-breaker for RAD developers. In this session, we will define some architectural aspects of SOA, ORM and MVC/MVVM, and what our Open Source mORMot framework offers to ease this transition.