Is it permissible to use a method of creating a website that shortens long links into small links for personal use, knowing that it prohibits pornographic or sexual advertisements and does not rely on usurious money?

The fundamental principle concerning all types of transactions is permissibility, unless there is evidence to prove their prohibition. Therefore, there is no harm in working for this company or any other, as long as its work does not involve a reprehensible act that would necessitate prohibiting work with it, such as publishing links to forbidden pages, advertising forbidden things, or if their advertisements include reprehensible elements like images of women.