This article is a case study of important design principles in the area of object-oriented programming languages aimed at solving maintenance problems in software systems. This study aims to deepen these principles with bibliographic research in order to improve the web system of a real company by passing on the knowledge gained to its team of programmers, but it can also serve any programmer who wants to know these principles better and wants to code better. quality in order to maintain their systems. The main findings of this study indicated that there was a noticeable improvement in the understanding of these principles by the programmer team.
