Hiring in marketing is a minefield, especially from the SEO side. Here's my take.
first, any decent technical SEO isn't going to do a take-home assignment for you. The people i know who are actually good at this don't hurt for work - they're already booked with clients or freelancing on the side. Asking them to spend hours on a made-up task for a job they might not even get? You're basically filtering for the desperate, not the best. That's a yellow flag from me.
on personality traits: if you're going to use phrases like "good moral compass" in your hiring criteria, you need to define what that actually means. I once worked for someone who threw that around a lot. Turned out it meant "agrees with my personal biases" - not exactly a robust or legal screening metric. without a clear definition, you can't interview for it consistently, and you'll just end up hiring people who happen to mirror your own quirks.
I've found green flags easier to spot than red flags in interviews. Red flags tend to be intangible - you sense something's off but can't pin it down. Green flags are patterns you can actively look for. One i rely on is how someone thinks in real time. I'll throw in a slightly absurd question - like "How would you explain canonical tags to a ten-year-old?" - and I'm not testing their canonical knowledge. I'm watching how they structure their answer, whether they recover from the curveball, and whether they can communicate a complex idea simply. if they freeze completely, that's a sign they'll need a lot of hand-holding later on tricky SEO issues. Works brilliantly for senior roles, probably overkill for juniors.
Also, if you're hiring for a function you're not fully confident assessing yourself - like technical SEO when you're a generalist - bring in someone whose judgement you trust. I've been on the other side of that table a handful of times, dragged in as a favour for a mate. they usually buy me a beer for my time. I'm not pulling any punches because it's not my job to lose - I'm just giving an honest read on their technical depth. that outsider perspective catches things you'd miss when you're rushing to fill the seat.