17 y/o, interned at PE firm over the summer, Harvard legacy. Need advice on my future

1) Apart from Harvard, because you have legacy there (which is a stupid system but if it helps you out, use it I guess): Apply to schools at least 1-2 tiers down from the Ivies. Your app will be wasted at the Ivies because your test scores and extracurriculars just aren't good enough. Think about e.g. Duke, Georgetown (non-SFS), maybe even Northeastern type of schools. All of those have decent finance placement, although someone who's gone there could tell you more about whether the big banks recruit on campus.

Also consider public schools like Indiana, Wisconsin, Rutgers - places that send people to NYC and Chicago, albeit more likely to smaller shops working on smaller deals. Know that at a larger public school, getting into the school is step 1, then you most likely have to apply for a more selective club/program within the school to maximize your chances of landing IB (Indiana Kelley's IBW is a good example of this).

Finally, consider small liberal arts colleges like Bowdoin or Amherst (East Coast) or Pomona and Claremont McKenna (West Coast) as those schools punch above their weight in the NYC/Boston and LA/SF finance scenes, respectively - this will require you to do more active networking, though, as I doubt banks come to those campuses to recruit because the schools are just too small.

2) Taking a step back, you're 17. You may think you want IB now, then decide you want to be a marine biologist halfway through your freshman year of college, then take a great literature class your senior year and end up becoming a mystery novelist. I encourage you to think carefully about what kind of college experience you want, and how you can set yourself up to maximize your personal/social development and academic growth no matter what career path you end up pursuing after school. If I had to go back and do college again, I would spend more time meeting new people and building friendships that would last beyond school, and less time worrying about all the pre-professional grinding and virtue signaling. As a corollary to this, there are tons of great schools out there. I know people who are amazingly talented and professionally successful who went to Sacramento State, and complete fuckups who went to Yale. Just apply to several schools that would provide a decent combination of name recognition, academics, and "fit" with your subjective preferences (e.g. geography and size), and ideally leave you with minimal debt afterward.