I was contacted by a recruiter for a 12-month contract position as a Data Engineer. The process started with an initial discussion about my experience and expectations, followed by a coding round.

Coding Round:

This round lasted one hour and involved:

• SQL: Questions based on a schema with four tables, focusing on aggregation and joins.
• Python: A problem to identify uncommon elements between two lists using only a brute-force method. The emphasis was on logical thinking and problem-solving. The interviewer was very helpful, encouraging discussions about my approach when I got stuck.

Other Rounds:

• Cultural Fit: Questions based on high-impact scenarios from past experience.
• Data Model Design and SQL: Designing a data model for a food delivery service and solving SQL questions based on it, e.g., identifying customers who didn’t order from a specific restaurant or at all.
• Python Problem-Solving: Tasks included concatenating elements from lists in a dictionary and formatting concatenated items and values in a given structure.

Throughout the interview process, the focus was on problem-solving and discussion rather than just coding. The recruiter and interviewers were supportive, making it a positive and satisfactory experience.

1. Identify the uncommon elements between two lists. You must use only the brute-force method while solving this; you are not allowed to use sets or any similar data structures. This is to test mostly your logical thinking.

2. Given a dictionary with two items, if the values are lists, concatenate all elements from list1 with list3 from the values.

3. Given a dictionary, concatenate the item and values in a certain format.

4. Design a data model for a food delivery service.

5. Which customers did not order from a particular restaurant (let's assume the restaurant ID is 3)?

6. How many customers did not order at all?