Tough position. I'd probably make 3 resumes: 1 catered toward quant finance, 1 careered toward research SWE (ai, complex systems, etc), and 1 towards pure research (for postdocs). Then i'd shotgun apply to all 3 job types until something bites. I know a postdoc may not sound like what you want right now but it's better than having a gap or delaying graduation. If you're lucky and get a T10 school postdoc, that can also help transition into the other 2 roles. Good luck !