- You may be looking for the production crew title of the same name.
Designers were time travellers who "designed" changes to the established timeline.
Designers were hired to alter time for many reasons - for example wealthy clients or corporates wanted a change to a specific aspect of the past to help in their favour. The change in the timeline could sometimes be truly intricate. People could be programmed meticulously to give them the right background to make the design work.
The Time Lord Berenyi became a Designer after graduating from the Academy, although the profession had been banned by her people for a long time. She designed the assassination of John F. Kennedy. (PROSE: Untitled)