Hey XY, Sorry for the cheeky reach-out. I‘ve already applied to the XZY role and just wanted to say I‘m really interested because it seems like it could be very good fit for both sides. I see you‘ve been using [tech] a lot, which I‘m personally a fan of, because it has [upside]. Btw, are you also using [tangential other tech]?

Or alternatively, ask some questions around team structure and roadmap - good leads like it when people are interested in what is likely their field of work.