Do major posekim have research assistants?

Like how secular judges might hire clerks? And how does one typically go applying for the job? I was reading one of the teshuvot of Maran haRav Ovadia zt”l, and the breadth of reference he displayed for historical pesakim is just astounding. It’s hard to believe that one person would be able to spend all of that time tracking down specific references to obscure writings, especially given the diversity of topics he covered.