Data Scientist Interview - Uber | AB Testing + SQL

👉 Land Your Dream Data Job. Visit www.datainterv...
👉 Join the Data Scientist Interview Bootcamp: www.datainterv...
Do you have a technical interview lined up for the data scientist interview?
Here's a 45-minute mock, technical screen conducted by a Sr. DS at a product company. The technical screen for most product-based roles is usually 45 minutes with SQL questions and AB testing.
👉 Watch how the candidate approaches the interview questions. And, if you want the rest of the video (the feedback portion), visit www.datainterv...
What are the benefits of enrolling in the Premium content? 👇
✍️ Learn from 30+ Hours of Video and Text-Based Courses created by interview experts who worked in top companies like Google and Meta!
📚 200+ Actual Interview Questions + Detailed Solutions - Get practice questions seen in actual interviews with detailed solutions solved by engineers from top companies (e.g. Google & Meta)
📝 Cover Core Areas in Technical Interviews including AB testing, product sense, applied statistics, machine learning, business case, SQL, data science coding and much more!
⭐ Become an SQL Pro with Interactive Pad with 100 SQL questions, easy to hard-level questions asked in top companies + highly optimized solutions.
🎥 Watch Mock Interview Videos with real candidates and an interviewer at top companies.
💭 Join the Private Chat Group to practice interview questions with peers and instructors. And, network with peers for your next job!
Join premium prep on 👉 www.datainterv...

[@brittosabu8401]

Q1:
SELECT
MONTH(order_time),
SUM(CASE WHEN DATETIME_DIFF(actural_delivery_time,predicted_delivery_time,MINUTE)

[@alexandretostes9002]

FORMAT_DATE('%Y%m', order_time) is an interesting alternative to avoid grouping months from different years

[@brittosabu8401]

@@alexandretostes9002 Right, missed that detail.
I think DATE_TRUNC() also works

[@khadijasultana8964]

where year(actual_delivery_time)=2021 is required. if multiple years of data present, then all years...month wise grouping will be done

[@AsefWafa]

Only mistake is both the case and the count(*) are integer values. So you want to convert it to a float to have decimal points. Easy fix to your code would be *100.0.

[@balanaveenvishal]

When MDE increases, the sample size decreases !

[@user-dt4uc8fu]

The interviewee does not understand what he said. Unfortunately, he now becomes interviewer. This explains why so many people who knows these stupid stuff failed the interviews.

[@orruijinal4568]

The definition of Power is in fact the probability of 'not' making the type II error, not the other way around mentioned by the interviewee. It is the probability of rejecting the null hypothesis when, in fact, it is false.

[@learningrealenglish4964]

ChatGPT can answer all the question related to code. So I don't think interviewer should ask those questions anymore. They would focus on how we solve the problems by ideas

[@gowthamchandanraju]

Why can't we use MIN function to determine the first order the driver delivered:
WITH zero_rating_first_order AS(
SELECT driver_id, MIN(order_place_time)
FROM delivery_orders
WHERE delivery_rating = 0
GROUP BY driver_id)
SELECT COUNT(zrfo.driver_id)*100/COUNT(DISTINCT(driver_id))
FROM delivery_orders JOIN zero_rating_first_order as zrfo
ON driver_id;
Or is there anything that I missed?

[@beyondtheclouds95]

0.07 is still not stat sig - going ahead and rejecting the null in that scenario would be wrong

[@zinomixx]

Awesome