In warehouse and construction work, if someone shows up at 7:30 AM on a Monday morning, odds are quite good that the foreman will have something for them to do. Maybe not that day, but maybe tomorrow, or maybe someone on the list above them won't show up that week and they'll get called. I made rent doing that in my early 20s and they even let me leave early sometimes to work on my internet business because I didn't have a family to support and maybe someone else had a bill they needed to pay and wanted my shift.
Why again does boutique startup need to interview 500 overqualified people? Hire someone right away and let them quit if they want to and hire someone else. It's just business for crying out loud.