I suspect the relative merits of different approaches depends on discipline and maybe geography, but in my area (interdisciplinary with applied mathematics and business most prominent, North America), a preprint, on ArXiV or elsewhere, should be essentially complete within the scope the authors have chosen for it to have. So you could upload a preprint which just doesdoesn't discuss those areas of your research you have not had time to complete, and which does not have all illustrations you might ideally want for the best possible exposition. A preprint may well end up significantly rewritten and expanded as part of a journal's peer review process, and it is only slightly disingenuous if you know fully well you're actually going to do that soon anyway.
However, importantly, your preprint should be complete enough you believe in good faith it could be publishable somewhere as-is, even if you are aiming for something better. We're not talking about a missing methododology or results section, or text that references still-nonexistent crucial figures or tables, in a way that can't be edited out without affecting the completeness of the paper.
If there are significant gaps which make this approach inappropriate, you have a work-in-progress draft, not a preprint yet. There is nothing precluding you from thoughtfully sharing that with colleagues, by email or even by say posting on your website, with all the pluses or minuses that entails. So if you want potential employers to have access, why not refer to it as work-in-progress or working draft and put a link to it stored on your research website for now?
Of course, in this case, you won't get credit for it as a "completed publication". But it is an option if it is unfinished but still interesting.