went through the Adobe senior/L5 loop earlier this year, remote. sharing what I know on the system design round since I couldn't find much specifics before I went in.
the system design round is 60 minutes, one interviewer. mine was a principal engineer on the Document Cloud side. scope was pretty broad: design a collaborative document editing service, think Google Docs-ish but don't actually say that. the main things they cared about: conflict resolution / CRDT vs OT (I went CRDT, got pushed on why) how you handle large documents vs tiny frequent edits storage: hot vs cold, what you're actually putting in blob vs structured DB cursors and real-time presence: WebSocket, SSE, polling tradeoffs
nobody expected a perfect whiteboard. what moved the needle was whether I could articulate the tradeoff space confidently. I got interrupted with "why not just X" about five times. they wanted to see how you handle that, not whether you had the perfect answer upfront.
difficulty: honestly easier than Google/Meta system design. more conversational. the interviewer was technically sharp but collaborative, not gotcha-y.
one thing that surprised me: they spent about 10 minutes on the API layer, specifically REST vs GraphQL and whether you'd ever expose a batch mutation endpoint. I think that's specific to Creative Cloud / Document Cloud context so might not come up in other orgs.
for prep: I'd drill distributed real-time systems, CDN design, and event-driven architectures. Grokking System Design is fine but it won't cover the collaborative editing case. look at the CRDTs section in the Designing Data-Intensive Applications book.
leveling at Adobe is a bit different than Meta/Google. L5 here is roughly equivalent to senior/IC4 but the bar on system design is lower than Meta E5 in my experience. comp was decent but not top-of-market (posted elsewhere in this thread).