I kicked off by explaining a basic architecture for the autocomplete system, suggesting a trie for fast lookups. The interviewer seemed engaged and asked about the trade-offs of using a trie versus a database solution.

I veered a bit off track trying to justify my choice, which might've rattled my flow. I mentioned caching the results to improve performance, but I didn't fully elaborate on the scaling aspect, which seemed to leave the interviewer a little puzzled.

The follow-up questions focused on handling large datasets and real-time updates, which I struggled with but did my best to respond. Overall, I felt strong about my initial design, but I could sense the concern over my depth of knowledge in handling complex issues.