How would you improve engagement for a social app feature with declining usage?

"The process was more rigorous than anything I’d done at other big tech companies, but the recruiter was accurate and helpful about what to prepare, which I really appreciated. A few things did catch me off guard: one round was more execution- and tradeoff-heavy than I expected, and the bar for structured, concise answers felt very high throughout. Overall, it was challenging but fair, and I came away with a positive impression of the process."