Not a Cloudflare recruiter specifically, but I've had a lot of candidates come to me after going through their loop, and I've placed people there. Here's a pretty accurate picture of what their recruiter screen covers.
First: the CF recruiter call is NOT a formality. Some companies use the recruiter screen just to confirm you exist and can speak in full sentences. Cloudflare's is more substantive.
Expect about 30-45 minutes. The recruiter will cover: Your background and why now, why Cloudflare. They care about the 'why CF' answer. Mission-alignment matters to them more than most infra companies. If you don't have a real answer ('I use their products,' 'I care about internet infrastructure,' 'my current role doesn't have the scale'), it shows. Role fit: they'll describe the team's current focus and ask you to react. Listen for what they're describing, because it tells you what they're actively building and what they'll test in the technical rounds. Salary expectations. They ask early. They have bands and they'll tell you if you're out of range rather than waste your time. In my experience this is one of the more transparent processes on comp range. Visa/authorization: standard, they ask it. Timeline. They move at a decent pace but they'll ask when you need to make a decision by. Tell them if you have competing offers.
Things that seem to kill candidates at the screen stage: vague answers about why Cloudflare ('it's a good company' is not an answer), or having done zero research on what the company actually does. They're not Stripe, they're not AWS. Know what edge network infrastructure means.