TL;DR: Their recruitment is a mess. Avoid at all costs.
Process: 2 interviews + coding assignment.
First interview goes okay. Recruiter and developer on the call. Good chat with the developer about tech and what they do.
They agree with the agency recruiter to send the coding assignment before the weekend. This doesn't happen and it's sent early in the week asking to complete it in 24 hours so they can review it. Given it's a coding assignment that takes a few hours of focused work to get a decent submission ready, they must think that we all sit crossing our arms on a weekday, ready to take their assignment. This obviously gets pushed back as it's unacceptable because I have work to do on that day (yes, they knew this, but didn't care).
The pair programming interview goes well, with a couple of cool and knowledgeable developers. However, they didn't really have a code template ready. Apparently, that's somewhere but they don't know where - another failure of the recruitment department as they don't make sure everything is in place. But no problem, we just create a project from scratch and it leads to a good session that leaves me with a good feeling about the development team.
Then, the legendary incompetence of the HR people shines at its greatest: once I get the contract, they say that it's unacceptable that I'm outside the UK for longer than 30 days, as they have some policy forbidding this. Given I'm a contractor, the work is going to be done remotely for the full length of the contract, and there is a global pandemic and a second wave in Europe right before Christmas (people go home for Christmas given the work is done remotely, right?), this is silly at best. The contract doesn't get signed for this reason, wasting weeks of my time, as I made it clear that I would spend a few weeks abroad during the first interview where the recruiter should have taken a note.
To the CEO: fire the HR people responsible for losing good developers for stupid reasons, if you don't want them to destroy your company.