Your question is Facebook Comments Storage Conceptual. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How does Facebook store comments?
Asked in the Managerial round (technical architect) stage. Listed under DBMS.
Explain an end-to-end design for comment persistence and access, including the data model, partitioning, indexing, consistency, caching, and any ML used for moderation or ranking. Address how the design handles writes, reads, edits, deletes, pagination, abuse, failures, and operational monitoring.