I'm still shocked at the number of employers who don't create one before they start looking for somebody. Especially those who don't think about how the new hire will fit into the existing organisation.
For example, I've seen this pattern multiple times.
a) Lead Developer (let's call 'em Mary) gets massively overloaded. No time to do the numerous things she's asked to do.
2) "We need another Mary" is as far as the job spec goes.
3) They find "Bob" who is, indeed, mostly another Mary. Bob gets pulled off onto NewFunProject, since Mary is waist deep in keeping CoreCompanyProduct running. Pattern repeats.
4) Mary rapidly gets rather annoyed that Bob gets to play with all the fun new projects, and promptly finds herself a nice new job. Walking away with a head's worth of CoreCompanyProduct that never got to Bob.
5) Bob gets massively overloaded. Goto 2.
Hiring is not what you should do to fix a short term problem.