I'm an applied math and data science student currently doing undergrad research in statistics. I don't want to dox myself, but it falls under optimization research. It's a good mix between math and data science, but I want to understand my chances when applying to graduate school in a couple of years. I'm talking in reference to competitive math programs, such as HYPSM and CMU (I have specific schools in mind).
This isn't general grad school app advice, although I'd love to hear it out as well! I've also seen that similar questions have been asked elsewhere on here, but I'm not sure of the mathematics admissions climate in particular. Specifically, I'm wondering how important it is to do research directly within math, even if your research interests are an "indirect" branch of math.
Edits: Any added info based on feedback from y'all, I'll add here.
Geographically, I'm from the US. I go to a southern R1.