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Course Curriculum
Product Case Studies
Introduction
LockedHow would you improve engagement on FB?
LockedWe are launching a new driver app with a better UI. The goal is increasing driver earnings by increasing their number of trips. Outline a testing strategy to see if the new app is better than the old one
LockedGive an example of a case in which you run an A/B test, test wins with significant p-value, but you still choose to not make the change
LockedDo you expect that Uber trips without rider review have been better, worse, or same as trips with reviews?
LockedA given category of an e-commerce marketplace, for instance jeans, is not doing well. How would you estimate if it is a demand or supply problem?
LockedWhat are the drawbacks of using supervised machine learning to predict frauds?
LockedIf 70% of Facebook users on iOS use Instagram, but only 35% of Facebook users on Android use Instagram, how would you investigate the discrepancy?
LockedWe made a change to our subscription offering adding new features. We expect this to increase subscription retention. How can we test if the change is successful?
LockedDo you think it is better to target ads based on user demographic or behavioral characteristics (past browsing experience)?
LockedWe ran an A/B test. Test won, so we make the change on the site for all users. But after waiting for some time, we realize that the new version of the site is not performing better than the old one. What could be the reason?
LockedYou are launching a messaging app. Define 2 metrics that you'd choose to monitor app performance during the first months. Why you chose them?
PreviewWhich feature would you add to WhatsApp?
LockedYou have to predict conversion rate on Airbnb using user country as one of the input variables. How would you deal with the missing values in "country"?
LockedHow to estimate the value of a user coming to your e-commerce store when they land on your home-page for the first time?
LockedHow can we tell if two users on Facebook are best friends?
LockedWhich variables are important to predict a fake listing on eBay?
LockedExplain the drawbacks of running an A/B test by market (i.e. all people in one market get version A of the site and another market version B)
LockedHow would you measure the performance of the customer service department?
LockedFB - Should we add a love button?
LockedHow would you use data to evaluate if it makes sense to implement two-step authentication when users log in?
LockedAt Facebook we use as a metric number of likes per user per week. And, each week, we check it year over year to control for seasonality. This week the metric is dramatically down. How would you find out the reason? Logging is fine as well as the query we used to get the data
LockedWe are running 30 tests at the same time, trying different versions of our home page. In only one case test wins against old home page. P-value is 0.04. Would you make the change?
LockedEach user on our site can be described by 100 continuous variables. What's the probability that a user is an outlier on at least one variable?
LockedLinkedIn has tested a new UI with the goal to increase the number of likes per user. They test it by giving the new UI to a random subset of users.
LockedDescribe one example of a classification problem where the cost of a false positive is way higher than false negative as well as the other way round
LockedHow to calculate for how long I should run an A/B test?
LockedSuddenly, our dashboard shows that the number of picture uploads per day by Internet Explorer users went to zero. What could be the reason?
LockedLinkedIn has launched its first version of the People You May Know Feature. How would you isolate the impact of the algorithm behind it w/o considering the UI change effect?
PreviewHow would you find out if someone put a fake school on LinkedIn? I.e. they actually didn't attend it
LockedYou are supposed to run an A/B test for 3 weeks based on sample size calculation. But after 1 week, p-value is already significant with test winning. So your product manager pressures you to stop the test and declare it a winner. What would you tell her? Explain in layman's terms
LockedWhat are the issues with splitting a small dataset (<1K events) in training/test set? What would you do then?
LockedUsing LinkedIn data, how would you predict when someone is going to change job? Assume you can use all LinkedIn user activity data
LockedBetween the following two metrics, which one would you choose to measure response time of an inquiry at Airbnb: percentage of responses within 16 hrs or average response time considering only responses within 16 hrs?
LockedAt FB, we found out that users with filled out profile infos (age, hometown, etc.) are more engaged than those without. Therefore, we figure out a way to fill out those infos automatically for all users hoping it would improve engagement. However, engagement barely changes. Why?
LockedYou ran an A/B test last year and it lost. When would it make sense to re-run the same test today?
LockedHow would you identify if an advertiser is using clickbait techniques without having a dataset with labeled events?
LockedWhat are the most important parameters in a Random Forest?
LockedIn on-line gaming companies, do you expect the average revenue per user to be larger or smaller than the median revenue per user?
LockedHow would you increase revenue from advertising clicks if you were working for an ads company (i.e. Google, FB, etc.)?
LockedGive an example of a site change that we can't test on a subset of users via a controlled experiment. How would you estimate the impact of that change?
LockedAdditional product DS questions included in the full course
LockedFollow up steps to prepare for the interview
LockedAirbnb wishlist feature
PreviewDS Live Assistant App example with video recording
LockedCategorizing Coding Questions
How does the data science coding interview work?
LockedCourse prerequisites and material to build the foundations
LockedRecurring themes - Growth metrics
PreviewRecurring themes - Percentile, top X, or ranking
LockedRecurring themes - Dealing with dates
LockedRecurring themes - Bidirectional connections between users
LockedRecurring themes - When does code optimization actually matter in interviews?
LockedRecurring themes - Threshold-based metrics
LockedSpecific job interview advice
LockedCoding questions with solutions
A framework to solve them all
LockedCalculate user churn
LockedCreate user sessions
LockedSubscription upgrades
PreviewIdentify fraudulent advertisers
LockedTotal messages exchanged
LockedUser segmentation
LockedRanking users within groups
LockedCalculate percentile
LockedA specific approach for the median
LockedTime delta between consecutive events
LockedFind the first power user
LockedCalculate total and running values
LockedFinal recommendations on SQL-like questions
LockedProbability Coding Questions
Takehome Challenges
Introduction
LockedINSIGHTS: Conversion Rate with solution
LockedA/B TESTING: Spanish Translation with solution
LockedINSIGHTS: Employee Retention with solution
LockedML: Identifying Fraudulent Activities with solution
LockedINSIGHTS: Funnel Analysis
LockedA/B_TESTING: Pricing Test
LockedML: Email Marketing Campaign
LockedML: Song Recommendation
PreviewML: Clustering Grocery Items
LockedML: Credit Card Transactions
LockedA/B TESTING: User Referral Program
PreviewML: Applying for a loan
LockedINSIGHTS: Sessionize user activity
LockedML: Optimization of Employee Shuttle Stops
LockedINSIGHTS: Workplace Diversity Analysis
LockedMETRICS: Hotel Search Data
LockedA/B TESTING: Engagement Test
LockedINSIGHTS: Video Sharing Analysis
PreviewINSIGHTS: Subscription Retention Rate
LockedMETRICS: Ads Analysis
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