An Exhaustive Collection of Amazon SQL Interview Questions for Data Roles

Cracking the SQL interviews at Amazon is no easy feat. As one of the most sought-after tech companies, Amazon’s interview process is notoriously challenging, featuring multiple SQL rounds for data roles like Business Analyst, Data Analyst, Data Scientist, Data Engineer, and Business Intelligence Engineer (BIE). Whether you’re gunning for a data role at Amazon or simply looking to sharpen your SQL skills, this comprehensive collection of real Amazon SQL interview questions will help you prepare and stand out from the competition.

Why SQL Matters at Amazon?

Amazon is a data-driven company, and SQL (Structured Query Language) is the backbone of data analysis and manipulation. As a result, SQL proficiency is a crucial skill for data professionals at Amazon. From querying massive datasets to optimizing performance, SQL knowledge is essential for roles that involve working with Amazon’s vast trove of customer, product, and operational data.

The Amazon SQL Interview Process

The Amazon interview process typically involves several rounds, each with its own set of SQL challenges. Here’s a general overview of what you can expect:

  1. Initial Phone Screen: This round often includes basic SQL questions on topics like date manipulation, GROUP BY, and JOIN clauses.

  2. Technical Interview: Expect more advanced SQL questions during this round, covering topics like subqueries, window functions, and performance optimization.

  3. Onsite Interview: The final round is the most intense, featuring complex SQL queries, database design questions, and potentially a take-home SQL challenge.

Throughout the process, interviewers will assess your SQL skills, problem-solving abilities, and understanding of data modeling and database concepts.

Real Amazon SQL Interview Questions

Without further ado, let’s dive into a collection of real Amazon SQL interview questions across various data roles:

Business Analyst SQL Interview Questions

As a business analyst at Amazon, you’ll be expected to analyze data, generate insights, and communicate findings to stakeholders. Here are some SQL questions you might encounter:

  1. Average Review Ratings per Product per Month

-- Write a SQL query to get the average review ratings for every product every month.-- The output should include the month (in numerical value), product id, and average star rating rounded to two decimal places.-- Sort the output based on month followed by the product id.SELECT     EXTRACT(MONTH FROM submit_date) AS mth,    product_id,    ROUND(AVG(stars), 2) AS avg_starsFROM     reviewsGROUP BY     EXTRACT(MONTH FROM submit_date), product_idORDER BY     mth, product_id;
  1. Highest-Grossing Items

-- Identify the top two highest-grossing products within each category in 2022.-- Output the category, product, and total spend.WITH product_sales AS (    SELECT         category,         product,         SUM(spend) AS total_spend    FROM         transactions    WHERE         transaction_date BETWEEN '2022-01-01' AND '2022-12-31'    GROUP BY         category, product)SELECT     category,    product,     total_spendFROM (    SELECT         category,        product,        total_spend,        DENSE_RANK() OVER (PARTITION BY category ORDER BY total_spend DESC) AS rn    FROM         product_sales) rankedWHERE     rn <= 2ORDER BY     category, total_spend DESC;

Data Analyst SQL Interview Questions

As a data analyst at Amazon, you’ll be responsible for interpreting data, building dashboards, and compiling systems for data collection. Here are some SQL questions you might face:

  1. Histogram of Comments per User

-- Write a SQL query to create a histogram of the number of comments per user in January 2020.-- Assume bin buckets class intervals of one.SELECT     count_comments,    COUNT(*) AS num_usersFROM (    SELECT         user_id,        COUNT(*) AS count_comments    FROM         comments    WHERE         created_at BETWEEN '2020-01-01' AND '2020-01-31'    GROUP BY         user_id) subqueryGROUP BY     count_commentsORDER BY     count_comments;
  1. Unique Flight Routes

-- Write a query to create a new table, flight_routes, that displays unique pairs of two locations.-- Duplicate pairs (e.g., Dallas to Seattle and Seattle to Dallas) should have one entry.CREATE TABLE flight_routes ASSELECT     DISTINCT LEAST(source_location, destination_location) AS source,    GREATEST(source_location, destination_location) AS destinationFROM     flights;
  1. Cumulative New Users by Day

-- Write a query to get the cumulative number of new users added by day, with the total reset every month.SELECT     DATE_TRUNC('month', created_at)::DATE AS month_start,    created_at::DATE AS day,    COUNT(*) OVER (PARTITION BY DATE_TRUNC('month', created_at) ORDER BY created_at) AS cumulative_usersFROM     usersORDER BY     month_start, day;

Data Scientist SQL Interview Questions

As a data scientist at Amazon, you’ll be responsible for building machine learning models, analyzing data, and providing forecasting insights. Here are some SQL questions you might encounter:

  1. Product Purchase History

-- Write a query to output a table that includes every product name a user has ever purchased.SELECT DISTINCT    user_id,    product_nameFROM (    SELECT         u.user_id,        p.product_name,        DENSE_RANK() OVER (PARTITION BY u.user_id ORDER BY AS rn    FROM         users u    CROSS JOIN         products p    WHERE IN (SELECT product_id FROM purchases WHERE user_id = u.user_id)) subqueryORDER BY     user_id, rn;
  1. Distribution of Conversations per User per Day

-- Write a query to get the distribution of the number of conversations created by each user by day in 2020.SELECT     user_id,    created_at::DATE AS day,    COUNT(*) AS conversationsFROM (    SELECT DISTINCT        sender_id,        receiver_id,        created_at    FROM         messages    WHERE         created_at BETWEEN '2020-01-01' AND '2020-12-31') subqueryGROUP BY     user_id, dayORDER BY     user_id, day;

Data Engineering and Business Intelligence Engineering (BIE) SQL Interview Questions

As a data engineer or BIE at Amazon, you’ll be responsible for designing and optimizing databases, ensuring data integrity, and maintaining data pipelines. Here are some SQL questions you might face:

  1. Second-Highest Salary in Engineering

-- Write a SQL query to select the 2nd highest salary in the engineering department.-- If more than one person shares the highest salary, select the next highest salary.SELECT     salary AS second_highest_salaryFROM (    SELECT         salary,        DENSE_RANK() OVER (ORDER BY salary DESC) AS rn    FROM         employees e    JOIN         departments d ON e.department_id =    WHERE = 'Engineering') subqueryWHERE     rn = 2LIMIT 1;
  1. Manager with the Biggest Team Size

-- Write a query to identify the manager with the biggest team size.-- Assume there is only one manager with the largest team size.SELECT AS manager,    COUNT(*) AS team_sizeFROM     employees eJOIN     managers m ON e.manager_id = m.idGROUP BY     m.nameORDER BY     team_size DESCLIMIT 1;
  1. Shipments During Membership Period

-- Create a report displaying which shipments were delivered to customers during their membership period.-- If the transaction is shipped during the membership period, the is_member column should have 'Y'; otherwise, 'N'.SELECT     s.shipment_id,    s.customer_id,    s.shipment_date,    CASE        WHEN s.shipment_date BETWEEN m.start_date AND m.end_date THEN 'Y'        ELSE 'N'    END AS is_memberFROM     shipments sLEFT JOIN     memberships m ON s.customer_id = m.customer_idORDER BY     s.customer_id, s.shipment_date;
  1. Time Series Discrepancies

-- Write a query to analyze a time series dataset and identify potential discrepancies.WITH time_series AS (    SELECT         timestamp,        value,        LEAD(value, 1) OVER (ORDER BY timestamp) AS next_value,        LAG(value, 1) OVER (ORDER BY timestamp) AS prev_value    FROM         asset_prices)SELECT     timestamp,    value,    next_value,    prev_value,    CASE        WHEN next_value < prev_value THEN 'Potential Discrepancy'        ELSE 'OK'    END AS statusFROM     time_seriesORDER BY     timestamp;

This query uses the LEAD and LAG window functions to compare each value with the previous and next values in the time series. If the next value is less than the previous value, it flags a potential discrepancy.

Wrapping Up

Preparing for Amazon SQL interviews can be daunting, but with practice and dedication, you can ace these challenges. Remember to brush up on your SQL fundamentals, practice writing efficient and optimized queries, and be prepared to discuss database design and optimization concepts.

Good luck with your Amazon SQL interview prep! If you’re looking for more SQL interview practice, check out our SQL Interview Guide and our collection of SQL interview questions from other top tech companies.

Amazon SQL Interview Questions & Answers


How many stages are there for Amazon SQL interview?

The interview process typically consists of three rounds: a recruiter phone screen, a technical assessment, and an onsite interview. * Some candidates have up to 2 technical screenings before the onsite.

What is the best way to answer an interview question on Amazon?

To answer any of Amazon’s interview questions, you’ll need to use the STAR method to frame your answer around one (or more) of their leadership principles and use data to support your answer while including something about the company’s peculiarities.

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