mass recruitment; large-scale hiring
Used for recruiting many people at once, often in job ads, event staff calls, or membership drives.
We are doing a mass recruitment of engineers for a new business.
Large-scale recruitment of volunteer staff!
This shop is currently hiring a lot of part-time staff.
We're inviting lots of ideas for a new character.
We're currently in the middle of hiring a lot of new employees.
求人 refers specifically to job openings or job ads, whereas 大募集 can be used for jobs, event staff, members, or even ideas being solicited in bulk.
公募 stresses that applications are being publicly invited (e.g. for a contest or position), while 大募集 stresses the large number of openings or entries sought.
Compound of 大 (large) + 募集 (recruitment).