The phrase "to work on a large scale" means to perform or execute something in an extensive, grandiose manner. It implies that the task is complex and requires significant effort, resources, and organization to complete successfully. This expression can be used in various contexts such as business, science, engineering, art, etc., where individuals or teams are working towards achieving a goal on a large scale. For example, building a skyscraper, conducting research for a cure of a disease, organizing an international event, and creating a masterpiece painting are all examples of work that is done on a large scale.