First, your pool will be very limited. Second, your competitors will likely be very bad at hiring - too many résumés, nobody paying attention, etc.
Job fairs at universities were my favorite. There's a lot of variation in the youth. There are people who will be too smart to stay in the job pool and there are those too dumb to keep a job. And you get to talk to them, so it's a good way to associate a human with their resume.
So you can ask why this girl claims to be an expert in Python but has 0 years of experience, or what a degree in HR really means. Why does this guy request such low salary for so much experience. Then you get better at identifying the signals.
I also think that quick interviews are necessary. You're able to do those on the spot, which means one less process. It's also a lot more casual and honest, since neither of you have invested much effort into this. You end up talking more about the things you do that excite you, why you started the venture. And they talk about what they really want to achieve in their career. Again the youth are great here, because they fantasize. Veterans still have those dreams, but it's buried under several layers. But as a startup, the dream fulfillment is your edge, so this is a great way to practice pitching to hires.
