关于Onsite，这一轮总共三小轮：\nTake-home Project Review\nStats/Experimentation\nProduct Case Solving. 1point3acres.com\n\n以下内容需要积分高于 188 您已经可以浏览\n\nTake-home Project Review：\nProject是给了一组实验数据，让你分析是否Performance如何，给你的recommendation，注意要分析Revenue Impact。 这一轮只要做好准备就没问题，我的方向是先做Hypothesis Testing，注意面试官会问为什么用T-test/Whelch's T-test/Z-test，可以从数据的distribution来解答。然后进入我提出的Revenue的计算方式，注意Delivery Cost会随着Orders的增长而变多，Revenue %也不会无限的增长，Manually增加会有Risks，所以关键是如何Optimize这两个变量。最后Segmentation Analysis也是关键，要分析每个Segnment的performance是好是坏以及你自己的见解。\nStats/Experimentation:\n这一趴会有十个小问题，注意要复习一下基础的Statistics，Experiment Design以及Linear Regression相关知识。\n因为每个题基本都有一些前提需要直到，在这里进行一下总结，知道了这些就没啥问题了。\n- How long should you run the experiment?. .и\n- What to do if your data distribution does not follow a normal distribution?\n- How would it affect your results?\n- Someone proposes to take the log of highly skewed data, would that work? Why or why not?\n- Given three confidence intervals for each cohort, tell me what can you say about the results?\n- If we use linear regression instead of using traditional cohort analysis, would it work?\n- Here's the linear regression model performance, what can you say about the model?\n- R squared seems very low, what can you do to increase it? Would adding another covariate variable work?\n- What is the difference between Lasso regression and Ridge regression?. 1point3acres\n\nProduct Case Solving:\n问题是：Instacart offers two delivery options at checkout. Quick same-day delivery, or scheduled delivery at a later date. The same-day delivery is only available when we have enough shoppers during order placement. If not, we would disable it. Data shows that 2 out of 3 Sunday afternoons in Miami, we've disabled this function for users. How would you investigate the root causes of this?\n就不给我自己的答案了吧，重点要想一想如何衡量supply and demand balance的问题，用什么metric去衡量比较好。知道是因为shoppers在那个时间段不够导致的，怎么去解决这个问题？有什么risk？怎么设计实验去measure这个impact？\n. From 1point 3acres bbs\n\n\nSenior DS的面试，特别是Product类型的最在意的就是你对产品的理解有多深，面临的常见问题有哪些，像Uber，Doordash，Instacart这种multi-sided market产品最常见的问题就是如何balance supply and demand，想要答好确实需要提前思考一下。