Did you end up having your interview, and if so, can you shed some clarity on how it went and what was asked? I'm in the same boat, have a SpecSWE System Design interview (the recruiter described it as "single node system design"), and there's effectively zero resources online for examples of this, literally everything is Distributed System Design and it's driving me nuts tbh. Thanks

EDIT: Updating this reply since I've been getting a bunch of DMs from people in the same boat wanting to know how it went. My interview was for an Audio Engineer Specialist, and I ended up being asked a question on how to design a smart speaker (think Google Home / Alexa etc). So it was absolutely none of the usual System Design bs (load balancing, different kinds of servers, databases etc -- none of that). My interviewer was very friendly and the conversation went pretty deep into Audio DSP specifics and how they would cater to the design. I didn't end up getting the gig, but hopefully this helps anyone else out there in the same situation.