Ask HN: Your way to screen potential developers for your team?

This is tough, it seems like people can just say "Yeah I can do that." I don't mean to be "discriminating" either but when you see how their sentences are formed it's concerning. I guess you can test their skill with a paid task but it also seems easy to just look things up copy/paste and send it in. While that gets the job done, is that person actually competent.