My Department currently has one staff member of the Department who retired, and was re-hired some months later as part of an open competition.
In relation to Public Sector workers, this is a matter for the bodies themselves.
The Department makes use of the expertise of retired members of the Department for the purposes of selection processes including the short listing of candidates and interviewing. In 2015, four retired members of the Department served on interview boards while to date in 2016 two retired staff members have served on interview boards.
Currently my Department has re-engaged eight former members of staff as part-time Locum Tenens Veterinary Inspectors on a contract for services basis. In addition, one former member of staff has been re-engaged as a part-time Locum Tenens Quality Manager on a contract for services basis, to provide cover for other essential functions within the Department.