Senior Data Engineer Interview Questions

2,590 senior data engineer interview questions shared by candidates

A developer on the team wrote an ETL that runs once a day as a Spark job. Every day it reads a CSV file that shows the total value of each customer's transactions of that day and writes them as a parquet file partitioned by date and customer id. Below you can see an example of the CSV file. Note that each customer has one entry representing the total transaction value it did on that day. However, sometimes the CSV file contains a correction for a sum reported in the past. For example - this file represents the transactions on 1/10. You can see that customer 1002 has 2 entries. One for 1/10 and one for 30/9. This means that the total sum of transactions the customer did on 1/10 is 70, but the total sum of transactions it did on 30/9 was 40 and this sum should replace the value already reported on 30/9. current date file: 2020-10-01 date,customer,price 2020-10-01,1000,40 2020-10-01,1001,10 2020-09-30,1002,40 2020-10-01,1002,70 2020-10-01,1003,10 2020-09-29,1004,10 2020-10-01,1004,10 This function represents the ETL. It runs once a day with a string representing the current day. It reads the CSV file, does some transformations, and writes it. Please help us find the bug in the code above, and return the right results
avatar

Senior Data Engineer

Interviewed at AppsFlyer

4.1
Mar 16, 2023

A developer on the team wrote an ETL that runs once a day as a Spark job. Every day it reads a CSV file that shows the total value of each customer's transactions of that day and writes them as a parquet file partitioned by date and customer id. Below you can see an example of the CSV file. Note that each customer has one entry representing the total transaction value it did on that day. However, sometimes the CSV file contains a correction for a sum reported in the past. For example - this file represents the transactions on 1/10. You can see that customer 1002 has 2 entries. One for 1/10 and one for 30/9. This means that the total sum of transactions the customer did on 1/10 is 70, but the total sum of transactions it did on 30/9 was 40 and this sum should replace the value already reported on 30/9. current date file: 2020-10-01 date,customer,price 2020-10-01,1000,40 2020-10-01,1001,10 2020-09-30,1002,40 2020-10-01,1002,70 2020-10-01,1003,10 2020-09-29,1004,10 2020-10-01,1004,10 This function represents the ETL. It runs once a day with a string representing the current day. It reads the CSV file, does some transformations, and writes it. Please help us find the bug in the code above, and return the right results

Why several switches in your previous roles? What was some feedback that you received in your previous roles? Did you leave your last job without any offer in hand? What are you looking for in your next job? Design a data quality system.
avatar

Senior Data Engineer

Interviewed at Coinbase

3.6
Mar 8, 2022

Why several switches in your previous roles? What was some feedback that you received in your previous roles? Did you leave your last job without any offer in hand? What are you looking for in your next job? Design a data quality system.

Viewing 151 - 160 interview questions

See Interview Questions for Similar Jobs

Glassdoor has 2,590 interview questions and reports from Senior data engineer interviews. Prepare for your interview. Get hired. Love your job.