How do I prepare for a senior SDET interview — what is actually assessed?

I have a senior SDET interview at a product company (Series C, ~200 engineers) in 3 weeks. I've done 2 SDET interviews before but always for mid-level roles. I'm trying to understand what "senior" actually means in the interview: - Is there more system design? (test infrastructure design, CI architecture?) - More focus on coding ability (live coding in Python/JS)? - Behavioral focus on mentorship, cross-team influence? - Or just harder technical questions about the same topics? Any interview experience at that level you're willing to share? Specifically what caught you off guard.