笔试题_数据科学_20190909

At Meizhi, we believe that well-rounded talents have the greatest potential to make a difference in this world. They1.Possess excellent coding skills;2.Are able to define an abstract concept distilled from the real world;3.Are able to foresee noise when carrying out scientific tests like a naturalscientist;4.Are truly independent thinkers;5.Are able to articulate their well-crafted thoughts to others and have thepotential to lead conversations and projects forward;6.Set eyes high and actively embrace seemingly insurmountable challenges;7.Have good life habits in general.The following eight questions are meant to explore the level of fit between your current skillset and the demand for the role. Your answer can be in Chinese or English.Part 1 – SQLGiven the below subset of a travel app’s schema, write executable SQL queries to answer the two questions below. Please answer in a single query and assume read-only access to the database (i.e. do not use CREATE TABLE).Assume a PostgreSQL database, server timezone is UTC.1.Between Oct 1, 2013 at 10am PDT and Oct 22, 2013 at 5pm PDT, whatpercentage of requests made by unbanned clients each day were canceled in each city?2.For city ids 1, 6, and 12, list the top three drivers by number of completed tripsfor each week between June 3, 2013 and June 24, 2013.On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 2 – Formulating a QuestionA retention matrix is used to represent the retention rates of different cohorts of new customers.1.How to define this matrix mathematically and what is the minimum data requiredto arrive at such a matrix?2.Write a script (in a single SQL query or combined in loops written in anotherlanguage) to obtain such a matrix from the data you assumed to have above.On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 3 – Experiment DesignA product manager on the Growth Team of the travel app has proposed a new feature. Instead of getting a free ride for every successful invite, users will get 1 Surge Protector, which exempts them from Surge pricing on their next surged trip.1.What would you choose as the key measure of the success of the feature?2.What other metrics would be worth watching in addition to the key indicator?3.Describe an experiment design that you could use to confirm the hypothesis thatyour chosen key measure is different in the treated group.On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 4 – Modelling, or Are You?You have a set of data describing a million customers’ various attributes such as demographics, entire purchasing history and app browsing history. It is therefore possible to model the data to predict each customer’s repurchase probability on an individual level. You are then faced with a limited marketing budget, which you can choose to allocate to a set of customers of your choice with the sole goal of maximizing the return brought by spending the budget.1.Briefly describe how typically such a model (e.g., logistic regression, random forestetc.) works in helping to select your set of customers?2.Have you worked on a similar model and what was it about?3.Is there any comment you would like to make on this question?On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 5 – Making an Argument in a Polite Yet Persistent WayDescribe a time when you disagreed with a general consensus or someone in a powerful position (e.g., your supervisor/client/parent/professor). You may want to use the STAR (Situation, Task, Action and Result) format. In particular, please be specific with1.how you presented your understanding of the facts;2.how you gained the other party’s perspective;3.how you managed both parties’ emotion.On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 6 – Our Role Models Say a Lot about Us, So Does Our Past Our FutureWho are your role models and why? What is the biggest “sacrifice” you have ever made in order to achieve any goal? Why would you consider that sacrifice at all?On a scale of 1-5 with 5 being for a perfect answer, where do you think your answer stands?Part 7 – Dealing with a Casual ScenarioSuppose that you arrived half an hour prior to the start of your scheduled interview, what do you do? Do you call up the interviewer to say you are here early? Do you sit at the reception playing with your phone? We are interested in the ways you respond to situations like this that arise almost on a daily basis as well as the habits and motivations behind your responses.Part 8As a junior member on the team, you will likely be dealing with much “mundane” work such as data cleaning before you get a chance to work on something “exciting”. How prepared are you with this?Help Us Help You (Optional)With a view to attract top talents to join our team, how do you think Meizhi can improve ourselves, be it in terms of this written question set, the entire recruiting process, or our business in general? Your feedback is much appreciated.。