Should I quit my Ph.D. program in scientific computing to become a software developer?
Only a partial answer but a fair warning, if you have not been keeping up with the news with respect to coding bootcamps: avoid it at all costs, seriously.  Learn to code by yourself through books - you have the "smarts" for this judging by your PhD in Sci Comp candidacy - or take CS courses at your school to pick up enough depth and breadth, which is what bootcamps severely lack (but make grandiose claims about).  I urge you to Google search some articles about this disastrous outcome that many bootcamp candidates are facing, e.g. stigma that they are unqualified coders.  E.g. Google, I think, now automatically desk-rejects applicants with bootcamps on their resumes, after hiring one too many failures.  Good luck.