FB Phone Interview SQL/Product

My very first interview in the new year... didn't pass. Hopefully it can help some of you ^ ^

SQL: FB is launching a 'composer' feature on the phone which helps user to post faster.

Table a:
date            user_id     session_activity
2019/1/1     1001        open
2019/1/1     1001        post

2019/1/2     1002        open

2019/1/2     1002   

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Curated Interview Questions from Top Companies

n newsfeed reduce by 1%?

Overall, average difficult level but I don't feel the interviewer is open-minded esp. when I explained my thought process in detail. We turned out go overtime.  Good luck everyone!

QIU DAMI :)

北极熊的梦想 发表于 2019-3-14 21:36
What if results come back and show that # posts up by 20%, but time spent on newsfeed reduce by 1%?  ...

个人感觉， 如果其他的条件不变，也没有event 和seasonality的影响，那么说明这个button是有用的，cause people post more posts.But the time spent on newsfeed decreased by 1% means that 1. the quality of the posts decreased because its easier to post rn and users could be more careless about the contents. 2. the increase fo the posts cause the newsfeeds crowded, users might not want to see a lot of non-close friends post but since the number of posts increased so there are more non-close friends there. 3. People might spend more time typing contents on their phone so they might spend less time on the feeds.
个人想法，欢迎补充

补充内容 (2019-3-17 20:33):
再补充一点
可能大家post 之后会更关注其他人和自己的interaction ，所以花费了更多时间在自己的post上，而看自己的主页是没有广告的
这些是短期

长期看post增多，interaction 也会增多，会增加用户的engagement

Thanks a lot for the posting and best luck with job hunting!

个人的思路,欢迎指正支招
Q1: successfully post ratio is the success metric
select (select count(distinct user_id) from a where session_activity='post')/(select count(distinct user_id) from a ) as ratio

补充内容 (2019-3-14 21:19):
select (select count(distinct user_id) from a where session_activity='post')/(select count(distinct user_id) from a group by date ) as ratio

多谢lz分享！Good Luck！

谢谢楼主的分享~！

darlingss 发表于 2019-3-11 06:57
个人的思路,欢迎指正支招
Q1: successfully post ratio is the success metric
select (select count(di ...

是不是可以再加个by day

Sarah0813 发表于 2019-3-14 04:33
是不是可以再加个by day

对的！当时太匆忙没仔细看谢谢提醒！

What if results come back and show that # posts up by 20%, but time spent on newsfeed reduce by 1%? 这种题应该怎么答呢。。。感觉很开放啊，有方向吗

谢谢分享！