I suspect this is a problem: it's hard to articulate the level of skill and competency of what we're trying to hire for. How does one describe a good engineer

I suspect this is a problem: it's hard to articulate the level of skill and competency of what we're trying to hire for. How does one describe a good engineer vs. a subpar one, when the only requirement listed is "knows Java, can code fizzbuzz bug free in 1 function less than 10 lines and in less than 5 minutes?" Something to that effect...