So, out of curiousity, what is SSIS architecture? Are you talking the underlying construction of it, the way to build selective data pathing, transformation components, error components, configurability, expressions construction, error row considerations? That question is so open ended you'd probably stunlock me into a few dozen questions to try to figure out what you were trying to ask.

Also, are you trying to give an interview and looking for good topics, or are you expecting to interview for a position and want an idea of what to brush up on? Those are two very different approaches, even though they look the same on paper.

Someone looking for good topics or questions I'd be able to provide a few particular questions to and if they have enough knowledge would extrapolate that into the necessary questions in an area, so they wouldn't be holistic, they'd be particular conversation spark points they'd be able to use to start guaging an applicant's real knowledge as they expanded off the answers the interviewee gave. If you're looking to interview, I can offer high level topics that you'll want to have general knowledge of and you'll have to dig into all the different applications of that knowledge, which means practice and experience.

I'm not sure which way you're trying to go here.