Breaking into AM during senior year of college

I might be able to shed some light on this, as I did full-time recruiting for a bunch of asset management firms in my senior year. My case is different from yours, since I worked in investment banking during my junior summer, but the general structure of the recruiting process still applies. I've written about this before, so I'll just copy-paste:

In short, the full-time recruiting process for Asset Management kind of sucks; it's a lot easier to get a buy-side role in most traditional asset managers going through the junior recruiting process instead. The major asset managers with undergraduate internship programs--think Fidelity, Wellington, MFS, T. Rowe, Putnam, AllianceBernstein, Eaton Vance, and bulge bracket banks with asset management divisions like JP Morgan and Goldman Sachs--already have very small intern classes (usually between 5 and 20 people), and like most places in finance these days, they usually try to fill their entire full-time classes with those returning interns. In that vein, Wellington and the asset management divisions at the bulge brackets did virtually no full-time hiring this year, only junior intern hiring.

That said, full-time recruiting for asset management doesn't suck quite as much as the full-time process for investment banking (where literally nobody gets the job except returning interns and a few accelerated lateral hires). In my experience recruiting this year, most asset managers still had a few spots open in their "regular" full-time recruiting process. How many? Not too many: when I interviewed at T. Rowe's bond research division, they were hiring 3 undergraduates in the country. I imagine it was more or less the same deal when I interviewed at both the equity and bond research divisions of Fidelity and Putnam. AllianceBernstein as well. Among the Boston-based asset managers, MFS was also hiring, although I didn't interview there.

Unlike in investment banking, it doesn't seem like most of the asset managers maintain accelerated recruiting tracks for lateral hires. You just submit your resume in September (side note: I literally got an interview from T. Rowe by submitting my resume online. It can really happen!), and then interview in October. Networking will certainly help, but as you can see, the process is less fast-paced than in banking, so you can still count on OCR and good old resume drops as well.

There are a few key differences in your case. Networking may be more important for you, even though you're at a target school, simply because it may be hard for you to clear the initial resume screening with only non-finance work experience. Additionally, you may want to consider applying to quantitive hedge funds/quant trading firms such as Two Sigma, D. E. Shaw, Jane Street, etc. simply on account of your background. They may be more amenable to your work experiences than traditional asset management firms, and it'd also be easier to craft the story you tell during your interviews.