A lot of discussion in this thread seems to be ignoring the subjectivity in defining what a job is. Job analysis and design is a fascinating topic and should become more important with "AI" changing the way we work. Unfortunately it's a topic covered mostly by HR consultants (it would benefit greatly from interest from the HN crowd).

edit: to avoid confusion, I'm talking about "a job" as "a collection of similar positions", an Job Analysis as a "a family of procedures to identify the content of a job in terms of the activities it involves in addition to the attributes or requirements necessary to perform those activities"