No referal, this is for Sr data engineer role, location: NY USA
I had phone interview with data engineer.
I was able to solve only 3 sql and 3 python

SQL
Products/ Sales/Promotions Schemas

1. % of transactions start and end date of the promotion (hint: int/int give you int so convert to float to get float)
2. % of products on some columns (Columns where flags with 0s and 1s)
3. select two media type counts (hint is use not like ('%,%') to filter multimedia types
   I felt, i was not confident on how to calculate %s. but she helped me.

Python

1. find given char in string ( i did with for loop instead of count() or counter)
2. replace None with previous list item. this tricked me little bit and took some time to solve. [She asked me not to update the existing list instead create new one]
   [None] ==> [None]
   [] ==> []
   [None,1,2] ==> [None,1,2]
   [2,None,3] ==> [2,2,3]
   [2,3,None,None,3] ==> [2,3,3,3]

All the best everyone!!!