Ask them to make some simple yet non-trivial feature, like a contact form on a web page. The overengineer will introduce a build system, several functional pro

Ask them to make some simple yet non-trivial feature, like a contact form on a web page. The overengineer will introduce a build system, several functional programming utilities, an HTTP client wrapper library, a DOM abstraction library, and maybe a full blown framework. The competent developer will write a <form> element with inputs.