Career Suggestion: Should I try to improve my manuscript or try to increase paper count after submitting PhD thesis I am a PhD student in Applied Mathematics. I submitted my Phd thesis and starting to apply for postdoc positions.

In my PhD thesis I have one work published in a tier 1 math journal and the other two works still unpublished. My question is the following: Should I submit the unpublished works in tier 1 journals and try to improve the quality of the manuscripts (with the reviewer's suggestions) or, submit to 2nd/3rd tier journals so that it gets accepted as soon as possible so that my paper count increases. I want to apply for faculty positions after 2 years from now. At this phase of my career what option should I choose?
If the question is whether to emphasize quality or quantity of publications, the answer is "both." But if you have to pick one, go for quality. People understand that peer review takes a long time, so it will not necessarily be held against you if your papers are still under review when you're applying for jobs. But it will be held against you if the papers are substandard in quality, or if they're published in mediocre journals.


  Should I submit the unpublished works in tier 1 journals and try to improve the quality of the manuscripts (with the reviewer's suggestions)


You should first of all improve the manuscripts as much as you can on your own, and with your advisor's help. Then submit to appropriate journals. Manuscripts do sometimes improve with referee comments, but just as often, a referee will reject a paper without detailed feedback (especially if the paper is clearly not good enough). Attempting to treat peer review as a free editing/consulting service would be a waste of the editor's and referee's time.