Should I mention that I work 100% remotely?

Personally, I think it depends on the context, but generally it's good to mention it if the role involves a lot of collaboration or if the employer has preferences about it. If you're applying somewhere that values physical presence, might as well be upfront from the start rather than creating friction down the road.

It's worth mentioning the 100% remote work, especially if you're applying to a company that works hybrid or in-office, because it can be a deal-breaker for them. On the other hand, if the job posting clearly says they accept full remote, no need to make a big deal out of it - you can mention it in passing if you really want only distance work, but it shouldn't be the priority of your application.

The thing is, you gotta read the job posting carefully - if it mentions being on-site or synchronous collaboration, you really need to flag it right from the start, otherwise you'll put yourself in an awkward spot at the interview. After that, if it's a role where nobody cares (dev, design, tech support), no need to make a big deal out of it.