How do I approach Data Manipulation (SQL/Python) interview questions?

Data Manipulation (SQL/Python) questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master data manipulation (sql/python) interviews.

What difficulty level is this interview question?

This is a easy difficulty Data Manipulation (SQL/Python) question, commonly asked during Technical Screen rounds at TikTok.

What role is this question designed for?

This question is commonly asked for Data Scientist candidates at TikTok during technical interviews.

Find top-paid employee per department | TikTok Interview Question

Quick Overview

This question evaluates a candidate's competency in SQL data manipulation, including aggregation, ranking, handling of duplicate and historical rows, tie semantics, and temporal data interpretation when determining the top-paid employee per department.

Tables

Assume the company stores employee compensation by department assignment.

`employee_dept_salary`

employee_id INT
employee_name VARCHAR
department_id INT
department_name VARCHAR
salary NUMERIC
effective_date DATE (optional; if present, assume you want the most recent salary)

Notes:

An employee may appear in multiple departments (e.g., matrix org or multiple assignments).
There may be multiple rows per (employee_id, department_id) (e.g., historical changes) unless otherwise stated.

Task

Write a SQL query to return the top 1 highest-paid employee per department.

Output

For each department, return:

department_id , department_name
employee_id , employee_name
salary

Follow-ups

If an employee can have records in multiple departments, does that affect the result? Explain.
What would affect the result (e.g., ties, duplicates, history rows)?
If the query can return multiple employees due to ties, but you only want one row per department , how would you enforce that (define a deterministic tie-break)?

Find top-paid employee per department

Quick Overview