OutSystems mainly relies on the visual development environment, which means that there is less need to write and debug code manually as developers employ drag-and-drop functionality and work with visual models. But it also supports traditional programming languages for increasing the customization and effectiveness level of the program. It enables the programmers to write methods using one or several languages like C#, JavaScript and SQL to manage the server-side and the client-side as well as to get in touch with the existing databases.