Hi everyone!
Maybe this info will be helpful
I had a phone interview
At first, the interviewer asked me about my experience with data.
Which ETL process I had designed wich tool used. Which methods I use to validate data and other sorts of situational questions about maintaining etl process (do not remember all questions)
Then he asked me about data modelling. Asked which primary key would I used a surrogate or natural key.
Which type of schema I will use for creating reports - means snowflake and star schema. (I described the difference between OLAP and OLTP).
Well to sum up
ETL - surrogate or natural key, situational questions, methods to validate data, tools
Data Modeling + DWH - OLAP & OLTP, snowflake and star schema, Normal Forms, tools for reports (unfortunately I didn't use Tableau)
Performance tuning - handle long running queries, Indexes, query plan, partitioning
SQL - two tasks in whiteboard (look questions below)
My advise repeat analytic and aggregate functions
It was my first interview with USA company
Even I didn't get an offer still it was a good experience
for me and I certainly will try again