2025年 4月电面 面了unread circle notification 最近的高频题\nSQL部分: | userid | ds | time | notification_type | status |\n+--------+--------------+------------+-------------------+--------+\n\n| 123 | 2022-01-01 | 1641044400 | direct | unread |\nTable: dim_circle_people\n+-----------+--------+------------------+---------------+------------+\n| person_id | userid | last_action_date | creation_date | ds |\n+-----------+--------+------------------+---------------+------------+\n| 1234 | 567 | 2022-01-01 | 2021-12-31 | 2022-01-05 |\na. How many people have two, three, or more than three accounts that were active during the last month?\nb. What percentage of active people with multiple accounts have unread notifications on any accounts?\nProduct 部分:\n对于有多个账号的人,需要把未读信息的账号置顶, sort unread notification accounts, 如何证明这个是一个值得launch得feature -- followup question--- 探讨看什么metrics\n如何setup experiment -- followup question: 为什么选择你用的这个metrics 作为来比较,因为我后面提到engagement 的问题,进一步跟进问了 如果说发现其实 test group的人大量进到置顶的unread notification account但是也是只停留了几秒钟话,你会认为这还是一个成功的feature吗? 这个最后的问题我答的不太好...