It seems like they were quite prepared. I'd say the screenshots, especially the LinkedIn profile and messages look pretty convincing. Usually, scammers are sloppy, they don't use Calendly, and you can often spot things like odd punctuation in their comments. But these guys seem professional.
One red flag for me is that I never do coding challenges before having at least one face-to-face video call. That filters out a lot of scammers.