Status: Data Engineer at a Healthcare company
Location: Austin, TX
Date: January 26, 2021
Contacted by a recruiter on LinkedIn and set up a call for phone screen.
Phone screen:
It had 10 basic questions: SQL and Python. Some questions were:
SQL:
Which is faster: UNION or UNION ALL? GROUP BY vs HAVING? What would be returned by the query: SELECT 1 + NULL?
Python:
Stack data structure follows which order? – LIFO Queue data structure follows which order? – FIFO Which data structure is used to store key value pairs? – Dictionary
The phone screen went fine, and recruiter scheduled the next Technical Screen coding interview.
Coding Interview:
As detailed in many other posts, coding interview has 5 SQL questions (25 minutes), 5 Python questions (25 minutes) and 5 minutes before and after the interview for meet and greet and any questions you have. The recruiter explained the process pretty well and provided resources to prepare for the interview. Use Glassdoor to get a sense of the type of questions that would be asked as all the questions that I got were present in the posts there. I am listing the questions that I was asked below:
SQL:
Do not remember the exact questions but was provided with 4 tables: Sales, Products, Transactions and Promotions. The schema is built, and you are able to execute the queries you write. Write queries to find percentages based on different scenarios.
Get comfortable with using SUM, COUNT functions with CASE statements and GROUP BY clauses and calculating percentages. Postgres handles division and casting differently than MySQL or other databases I have worked with. So, practice a few queries on Postgres before attempting the interview.
Python:
Count the occurrence of a specific letter in a string. Find the nth highest value given an unsorted dict. Given two lists, find the uncommon words. Replace None in a list with the last non None value.
I was able to answer 4 SQL questions and 3.5 Python (some test cases failed for the last attempted question) and have received the call for the virtual onsite interview. Will update this post once I am done with those interviews.
Attempting a FAANG interview for the first time and it's a little overwhelming for me. Please share any resources that you may have to help me prepare for the onsite interviews. I’ll appreciate your help.