The short answer to your question is no–at least in New York State, where I am licensed to practice law.
An interview is a discussion to see if an employer and employee are right for each other. It’s not a way for an employer to get some work done for free.
The interview process might involve writing or design samples, as well as a test. But doing work that the employer would otherwise have to pay someone to do is typically illegal.
For example, a law firm can probably assign a generic, hypothetical case to test the potential employee’s writing and research skills related to an issue the firm sees regularly. However, assigning research on an open case is likely work that must be compensated.
Similarly, a technology business could ask prospects to review sample code for errors. But if the corrected code is going to be used in a product, there should probably be some compensation (and clear transfers of ownership rights).
In most cases, the prospect might be deemed an employee at the moment the employer gets a benefit of commercial value.
Note that my language is intentionally inconclusive. This is general information and not legal advice. These situations are very subjective and will be reviewed on a case-by-case basis. Employers would be wise to consult employment counsel before implementing any “testing” done during the hiring process. Likewise, employees would be wise to question whether such requests are legal and consult their own counsel.
Not sure your interview process is compliant?
https://thirdearcr.com/master-your-employment-relationships/
DISCLAIMER
This post contains a general overview of unpaid work. It is not legal advice. If you require information or advice applied to your unique situation, please make an appointment to discuss it with an attorney experienced with the subject matter. Don’t rely solely on what you read on the Internet. Ever.