Ask HN: How would you measure if a job is meaningful?

I've grown impatient and a bit disgusted by how most job and contracting ads are focused on what stack is used and what benefits are offered.

It feels like these ads are not treating tech workers as creative people to whom doing meaningful work is important.

I've been working on a simple tool to help alleviate the situation a little, yet I'm curious: how would you gauge if a job is meaningful, if the "why" and "how" of it are worthy of your attention?

What do you expect from an employer or a client in order for you to feel valuable and meaningful in a position?