I was bit before by hiring specialists when I did not know what task at hands was, what metrics I should expect, what kind of timeline is reasonable, what potential gotchas are.

And for person with CTO title, I think it must have.

Don't hire a role you think you need until you're sure you need it. Sometimes startups think "we need an HR person" or "we need a marketing person" before those jobs are actually at the point where they require a full-time person.

But after your first few engineering hires, you will probably know well whether you need, say, a backend engineer. You will have people doing some of that work, and be able to look at your roadmap and estimate correctly.

But for first-of-their-type roles (like my marketing or HR examples), that's harder - often part of it is startup leadership thinking "we could be doing so much XYZ I don't know about", instead of "we're doing 10 hours of XYZ a week and I know we need 40".

Once you've decided you need the hire, you want to get a person as smart as possible.

I see this all the time in hiring and acquiring vendors. Management just wants to fill missing talent, but then can't tell they are getting mediocre work.

I've seen people who don't know how to market their product go out and try to hire a marketing guy. You might luck out and get someone perfect for you, but I've never seen it.

Usually they just end up wasting a lot of money and learning some hard lessons.