Why are hotel employees also called engineers?

Many titles are slightly different in different hotels, but their functions are similar. According to Zhihu's information query, many appellations are slightly different in different hotels, but their functions are similar. There are also some positions that hold two positions at the same time, or a manager temporarily plays the role of general manager-the general position title will not change according to the hotel's rules or management style, and some wooden hotels will set up unique positions according to their own needs.