Servian: Data Engineer Interview Questions

I don’t have all the answers, but I do have the questions

We interview for Data Science and Data Engineering roles in Sydney constantly. In this post we are going to tell you the technical interview questions we were asked. You will probably be asked the same thing. Companies are lazy. They will probably recycle their questions.

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The first round is a recruiter interview. Pretty standard behavioural stuff. I’ll assume you got past this.

Second Round Technical Interview

You’ll be asked 2 SQL questions involving window functions.

1. Find a rolling sum of amount as date increases
   Ans: Use a window function
2. Find a rolling sum of amount as date increases over a specific group
   Ans: Use a window function with a partition

Data Visualisation Question. What is wrong with this graph? Ans: It is a line graph that interpolates where there is no data. Mention the word “interpolation” for extra points.

Data Quality Question. How would you create a primary key when the id field is blank? Ans: Use the date parameter as a random number generator. You don’t need to overthink it.

Final Round Partner Interview

Don’t ask the partner to explain the question further. You will be marked down for doing so. Read the prompt. The prompt is as follows:

Find the total sales for NSW and the attribution to each staff member by product in NSW

You’re probably thinking that is unclear. I agree.

You will be given 3 tables:

You will be asked to calculate ‘attribution_price’ in the following table.

Ans: You can answer this question using 2–3 CTEs. You’ll need to use a cross join. To see the rough pseudocode check out our newsletter.

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Good luck interviewing!