Started by outlining high-level requirements for the chat app, including one-on-one messaging, group chats, and message persistence. Discussed potential components like the client app, server architecture, and database model. The interviewer nodded and engaged with deeper questions about scaling and user authentication. I proposed using WebSocket for real-time communication, which seemed to resonate with them.

When diving into scalability, I suggested sharding the database based on user IDs. The interviewer challenged me on how to handle message delivery guarantees and syncing states across clients. I felt confident discussing eventual consistency but stumbled on explaining the trade-offs clearly enough. I noticed the interviewer’s raised eyebrows when I faltered, which made me lose some momentum.

As the interview progressed, I could feel myself getting off track with some technical details, like explaining load balancing strategies in-depth. The interviewer asked clarifying questions around monitoring and logging but I quickly realized I had rushed through some important aspects, particularly around security measures. This led to a follow-up conversation where I tried to pivot back, but I had already lost the flow.

Overall, the experience was a mixed bag. I communicated well initially but struggled to hold the interviewer’s focus toward the end. I left feeling uncertain about my performance. Not a great vibe for an outcome, but who knows?