Design a Collaborative Editing System like Google Docs

This was a follow-up to [coding question/previous round]. The interviewer wanted to see how I would [scale the system/handle production concerns]. We talked about [monitoring, alerting, deployment, etc.]. Time was limited so we focused on [key areas]. The interviewer started with [basic requirements/functionality]. We covered [main topics like database design, API endpoints, basic scaling]. The focus was on [specific area]. Duration was about [X minutes].