Gig sites have their ups and downs. One of the most widely recognized meme sites is Craigslist. This is a job site that has helped many people hire waitstaff
BUT there is no guarantee that the people you find are what you are looking for. There are other sites like Upwork, Indeed, Glassdoor, etc. They are popular and heavily used by both employers and employees, but with this access to the multitudes, comes a multitude of issues.
Pros: Lots of employee applicants, ease of access online, and affordable.
Cons: Lottery when it comes to finding good candidates, no background check or work verification of applicants, you assume all of the risks.