What we know as electoral engineering is a set of technical tools aimed at the design or reform of electoral systems to better adjust them to the evolving reality of a country. Beyond design, however, there is a vast field composed of the actual practice of implementation of these reforms and the lessons learned from it through time. These pages, written from a practitioner’s and not a scholar’s point of view, highlight some of the lessons the electoral community learned through concrete experiences of design and reform of electoral systems in conflict areas, and proposes some best practices to contribute to the current debate on electoral reform in Chile.