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Amazon SQL Interview Questions (February 2024)

Tim S

Tim S

Tim currently works at FAANG as a data analyst. He's been in the industry for 5+ years and writes for Big Tech Interviews on the weekends. His favorite language is SQL and calls Denver, CO home.

Whether you’re practicing for an Amazon business analyst assessment and interview, data analyst, or data scientist, you’ll need to showcase your SQL skills to pass all the interview rounds. This guide is designed to help you brush up on your skills and prepare for your upcoming interview with confidence.

 

Table of Contents

  • Overview of Amazon’s History and Company Culture
  • Amazon Business Analyst Interview Questions
  • Amazon Data Analyst Interview Questions
  • Amazon Data Scientist Interview Questions
  • Frequently Asked Questions
amazon-intern-ba-2

Overview

Amazon is a giant in the tech industry and is known worldwide for its innovative products and services. From selling books in 1994 to becoming a multinational conglomerate with over 41 subsidiaries and brands, Amazon has come a long way. The company values its employees and provides growth opportunities, making it an attractive employer for professionals in the tech field.

In order to succeed in your Amazon technical assessment, it’s essential to have a solid understanding of SQL. SQL, or Structured Query Language, is a programming language used for managing and manipulating data stored in relational databases.

Amazon utilizes SQL in various aspects of its operations, from managing and analyzing large amounts of customer data to ensuring the smooth functioning of its e-commerce platform. If you’re looking to join the Amazon team, you’ll need to demonstrate your expertise in SQL and your ability to apply it in real-world situations.

In this guide, we’ll provide you with comprehensive information on Amazon’s company culture and give you an overview of what to expect during your interview. We’ll also provide tips and strategies for preparing for your interview and give you a chance to practice your SQL skills with real-world scenarios. With the right preparation and dedication, you’ll be well on your way to acing your Amazon SQL interview and landing your dream job.

The Amazon Analyst Interview Process

The Amazon Business Analyst Interview is designed to assess a candidate’s skills and experience in business analysis, strategic thinking, and data-driven decision making. This interview process is unique to the role of a business analyst at Amazon and may differ from a data analyst or data science interview.

During the Amazon Business Analyst Interview, you can expect to face a combination of technical and behavioral questions. Technical questions may include topics such as business analysis methods, market analysis, financial modeling, and data interpretation. Behavioral questions may include discussions about your experience working on projects, problem-solving skills, and communication abilities. 

The interview process may include multiple rounds, starting with a screening call and followed by an on-site interview. The on-site interview may include a case study presentation, group discussion, and one-on-one interviews with the hiring manager and team members.

To prepare for the Amazon Business Analyst Interview, it is important to have a strong understanding of SQL, business analysis concepts, market research methods, and financial modeling. It is also important to be familiar with Amazon’s business operations and culture. Additionally, practice case studies and be prepared to provide examples of your past experience and how you have applied your business analysis skills in real-world scenarios.

Amazon Business Analyst Intern and Full-time Interview Questions

  • Recruiter Phone Screen
  • Technical Assessment
  • Onsite

Round 1: Recruiter Phone Screen

The recruiter phone screen is the first step in Amazon’s interview process, and it is typically 30-60 minutes long. The goal of this interview is to determine if you meet the basic qualifications and requirements for the job. 

During the call, the recruiter will ask standard questions such as why you applied for the job, what about the job description stood out to you, your salary expectations, and when you can start. 

However, what many job seekers often overlook is that this phone screen is also an opportunity for the recruiter to assess your cultural fit. Therefore, it’s essential to be prepared to talk about Amazon’s Leadership Principles and to build rapport with the recruiter.

Types of questions to expect during your phone screen:

  • Why did you apply to Amazon?
  • What about this job description stood out to you?
  • What are your salary expectations for this job?
  • When can you start?

This sounds like a pretty standard interview process, right?

WRONG! This is a common rookie mistake.

While your interviewer needs to get these questions out of the way, they’ll also be analyzing you for a cultural fit. Make sure you’re ready to talk about the Amazon Leadership Principles at a high level.

Lastly, during this initial interview process, it’s a great opportunity to build rapport with the recruiter and pick up pieces of information as to why they’re hiring for this role.

This knowledge will help you decide which examples to use in subsequent interview rounds.

Round 2: Technical Assessment

The technical assessment is the second round of Amazon’s interview process and is typically 30-60 minutes long. This round will test your technical abilities, including your SQL skills and your understanding of data management and potentially Python. 

To prepare for the technical assessment, it’s crucial to practice your SQL skills and brush up on common Amazon SQL interview concepts. You can visit app.bigtechinterviews.com to practice and solve real SQL interview questions and hone your skills.

Types of Amazon business analyst interview questions:

  • Question: What is a DISTINCT clause?
    • Answer: Used to return only unique (different) values
  • Question: What is the difference between a UNION and UNION ALL?
    • Answer: Union extracts the rows that are being specified in the query while Union All extracts all the rows including the duplicates (repeated values) from both the queries.
  • Question: How do Window Functions work?
    • Answer: Window Functions execute calculations at the row level with a related set of values. Compared to using aggregate functions like SUM(), window functions don’t collapse the output of the rows into a single value. Rather, the output is returned for every row.
  • Question: What is the difference between a primary and a foreign key?
    • Answer: Primary keys are either a column or a set of columns in a table that hold uniquely identifiable rows in the table. While a foreign key could be a column or a set of columns in a table whose values correspond to the values of the primary key in another table.
  • Question: What is the difference between LEAD and LAG?
    • Answer: LEAD will give you the rows AFTER the row you are finding a value for. LAG will give you the rows BEFORE the row you are finding a value for

Have an upcoming technical assessment? Check out our SQL playground with the latest interview questions.

Round 3: Onsite (Final round)

The onsite interview is the final round of Amazon’s interview process and is an all-day affair. It consists of 4-5 consecutive interviews, including 1-2 technical interviews, which will test your technical abilities, and 2-3 behavioral interviews, which will focus on Amazon’s 16 Leadership Principles. The onsite interview is an opportunity to showcase your technical skills and to demonstrate your cultural fit.

The behavioral interviews will focus on Amazon’s 16 Leadership Principles, and it’s essential to have examples of each principle ready. To streamline your examples, try using the STAR format, which involves explaining the Situation, Task, Action, and Result of a situation where you demonstrated a particular principle. 

  • Situation: What was your exact situation?
  • Task: What were you required to do?
  • Action: What steps did you yourself own?
  • Result: What was the outcome of this?

Additionally, be prepared to be interviewed by a bar raiser, who is a senior manager responsible for ensuring that candidates are 50% better than current Amazon employees.The final round is an all-day interview consisting of 4-5 consecutive interviews. Their emphasis is largely around behavioral and cultural fit as they believe most individuals can come up to speed with their technical skills assuming they’ve passed the initial tech screens. 

Remember to speak slowly, clarify the questions, and walk them through the logic behind your solutions.

This last step is often overlooked. It’s not unheard of for someone to get an offer due to their logic, even though they might have not solved the problem correctly.

It’s extremely important that you have examples for each of these principles.

Common onsite Amazon business analyst interview questions:

  • Can you give us an example of a time you had to handle a difficult customer or situation?
  • How have you demonstrated the Amazon Leadership Principles in your previous role?
  • Can you walk us through a time when you had to collaborate with a team on a project?

Amazon business analyst technical onsite round is a crucial step in the interview process and often the final hurdle to securing a job offer. It’s a comprehensive and intensive day-long interview that typically consists of 4-5 consecutive interviews. The purpose of this round is to evaluate the candidate’s technical skills, problem-solving abilities, and cultural fit within the company.

The technical interviews in this round will focus on the candidate’s SQL skills and may also include some questions related to Python and data management. The interviewers will assess the candidate’s understanding of complex SQL concepts, their ability to write efficient SQL queries, and their problem-solving skills.

During this round, the candidate can expect to answer technical questions that are more challenging than the ones in the previous technical assessment. The interviewers will test the candidate’s weak points from the last technical assessment, so it’s crucial that the candidate has prepared well and ironed out their weak points. It’s recommended to practice solving real SQL interview questions on a platform like app.bigtechinterviews.com.

During the technical interviews, the interviewers will be looking for a deeper understanding of SQL and may ask more challenging questions than those posed during the initial technical assessment. It’s important to be prepared for these more challenging questions, to iron out any weak points from the initial technical assessment, and to be able to explain your thought process as you solve problems.

Common onsite Amazon business analyst SQL questions:

Amazon/AWS SQL Interview Question 36: Salary by department
Prompt: Write a query to find the average salary by department. Round the result to 2 decimal places.

 
Table: employee
+------+----------+---------+----------+------+----+----------+-----------+
|emp_id|first_name|last_name|manager_id|salary|dept|start_date|building_id|
+------+----------+---------+----------+------+----+----------+-----------+
|1     |hector    |bush     |1         |40000 |ops |2018-03-05|1          |
|2     |kim       |stewart  |1         |31000 |eng |2019-04-05|2          |
|3     |peter     |thompson |1         |31700 |ds  |2019-02-05|3          |
|4     |thomas    |henderson|1         |32000 |ops |2018-03-05|2          |
|5     |john      |free     |1         |35000 |eng |2019-03-08|3          |
|6     |tara      |glad     |5         |32000 |ds  |2019-01-12|1          |
|7     |linda     |bruss    |5         |30000 |ops |2020-04-19|3          |
|8     |forest    |gump     |6         |29000 |eng |2021-04-19|1          |
|9     |luke      |smith    |7         |28000 |ds  |2019-06-24|2          |
+------+----------+---------+----------+------+----+----------+-----------+

Solution

select
dept,
round(avg(salary),2) as avg_salary
from employee
group by dept; 

Amazon/AWS SQL Interview Question 38: Employees who earn the second-highest in each department

Prompt: Write a query to find the list of employees who earn the second-highest in each department

Table: employee
+------+----------+---------+----------+------+----+----------+-----------+
|emp_id|first_name|last_name|manager_id|salary|dept|start_date|building_id|
+------+----------+---------+----------+------+----+----------+-----------+
|1     |hector    |bush     |1         |40000 |ops |2018-03-05|1          |
|2     |kim       |stewart  |1         |31000 |eng |2019-04-05|2          |
|3     |peter     |thompson |1         |31700 |ds  |2019-02-05|3          |
|4     |thomas    |henderson|1         |32000 |ops |2018-03-05|2          |
|5     |john      |free     |1         |35000 |eng |2019-03-08|3          |
|6     |tara      |glad     |5         |32000 |ds  |2019-01-12|1          |
|7     |linda     |bruss    |5         |30000 |ops |2020-04-19|3          |
|8     |forest    |gump     |6         |29000 |eng |2021-04-19|1          |
|9     |luke      |smith    |7         |28000 |ds  |2019-06-24|2          |
+------+----------+---------+----------+------+----+----------+-----------+
Table: building +-----------+--------------+ |building_id|building_name | +-----------+--------------+ |1 |ss | |2 |vs | |3 |ts | |4 |zs | +-----------+--------------+

Solution

with employee_rank as (
select
emp_id,
first_name,
last_name,
dept,
row_number() over (partition by dept order by salary desc, start_date asc) as rank_
from employee
)
select
emp_id,
first_name,
last_name,
dept
from employee_rank
where rank_ = 2; 

Amazon/AWS SQL Interview Question 42: Number of times solved
 
Prompt: Write a query to find the number of times each question was solved and the total minutes needed and the difficulty level in the month of December 2018

Table: questions
+-------------+-------+--------+--------------------+
| question_id | level |  name  | added_date         |
+-------------+-------+--------+--------------------+
|453          |easy   |superbad|2021-04-05 10:00:00 |
|558          |medium |matrix  |2021-05-09 12:00:00 |
|841          |hard   |lucky   |2019-06-03 16:00:00 |
+-------------+-------+--------+--------------------+
Table: members +---------+-------------+---------------------+---------+ | user_id | question_id | start_time | minutes | +---------+-------------+---------------------+---------+ |1 |453 |2021-04-06 11:00:00 |45 | |2 |558 |2021-05-10 10:00:00 |80 | |3 |841 |2019-06-04 03:00:00 |35 | |4 |453 |2021-04-06 15:00:00 |53 | |5 |841 |2019-06-04 12:00:00 |90 | |6 |841 |2018-12-04 12:00:00 |3 | |5 |841 |2018-12-07 12:00:00 |90 | |3 |558 |2018-12-11 12:00:00 |45 | +---------+-------------+---------------------+---------+

Solution

select
q.question_id,
q."level",
count(user_id),
sum(minutes) as total_minutes
from questions q
left join members m on q.question_id = m.question_id
where date_trunc('month', m.start_time)::date = '2018-12-01'::date
group by
q.question_id,
q."level";

Amazon Business Analyst Interview Questions

Most common responsibilities of a Business Analyst:

  • Perform complex data analysis to identify opportunities to reduce cost
  • Design, develop and establish KPIs to monitor data analytics and provide strategic insights to drive growth and performance
  • Ability to perform/own reoccurring and ad-hoc business intelligence projects
  • Develop standardized metrics to evaluate and benchmark pertaining to short and long term network planning and forecasting
  • Communicate complex analysis and insights to stakeholders and business leaders, both verbally and in writing

How to prepare for the Amazon business analyst interview

You should prioritize at-least 60% of your time on the behavioral aspects of the interviews such as the 16 Leadership Principles and the remaining 40% focus on the technical components such as SQL queries and database management.

Read More: Amazon Business Analyst SQL Interview Questions

Amazon Data Analyst Interview Questions

Are you looking to work as a data analyst at Amazon? It’s important to understand the interview process and be prepared for each round. The interview process typically consists of three rounds: a recruiter phone screen, a technical assessment, and an onsite interview.

Interview format for a data analyst role at Amazon

  • Round 1: Phone screen
  • Round 2: Technical interview
  • Round 2B: Technical interview*
  • Round 3: Onsite (final round)

* Some candidates have up to 2 technical screenings before the onsite.

The data analyst interview will in a lot of ways resemble the data science interview. It’s going to be heavily focused on problem-solving, statistics, and your proficiency with languages such as SQL and Python.

Data analyst at Amazon will leverage a suite of languages such as R, Python, SQL, and must be able to support leadership by surfacing insights from complex data sets.

Round 1: Recruiter Phone Screen

The first round of the interview process is a 30-60 minute call with a recruiter. The purpose of this call is to determine if you meet the basic qualifications and requirements for the job. During the call, the recruiter will ask standard questions about your background, your experience, and your Amazon salary expectations.

But what many job seekers overlook is that this call is also an opportunity for the recruiter to assess your cultural fit. Therefore, it’s essential to be familiar with Amazon’s Leadership Principles and to be able to articulate your understanding of them. Additionally, this is a great opportunity to build rapport with the recruiter and gather information about the role and why they are hiring for it.

Round 2: Technical Assessment

The second round of the interview process is a technical assessment, which typically lasts 30-60 minutes. This round is designed to test your technical abilities, including your SQL skills and your understanding of data management. To prepare for this round, it’s important to practice your SQL skills and refresh your knowledge of common Amazon SQL interview concepts. You can visit app.bigtechinterviews.com to practice solving real SQL interview questions and improve your skills.

Round 3: Onsite Interview

The final round of the interview process is an all-day onsite interview. During this round, you will have 4-5 consecutive interviews, including 1-2 technical interviews and 2-3 behavioral interviews. The technical interviews will test your technical abilities, while the behavioral interviews will focus on Amazon’s 16 Leadership Principles. This is your opportunity to demonstrate your technical skills and cultural fit.

To prepare for the behavioral interviews, it’s important to have examples of each of the Leadership Principles ready. Using the STAR format (Situation, Task, Action, Result) can help you organize and articulate your examples. Additionally, be prepared to be interviewed by a “bar raiser,” a senior manager responsible for ensuring that candidates are 50% better than current Amazon employees.

Most common responsibilities of a data analyst
  • Understand how to use one or more industry analytics and metrics visualization tools (e.g. Excel, Tableau/QuickSight/MicroStrategy/PowerBI)
  • Knowledgeable in a variety of methods for querying, processing, persisting, analyzing, and presenting data.
  • Good understanding of data lineage: including sources of data; how metrics are aggregated; and how the resulting business intelligence is consumed, interpreted, and acted upon by the business.
  • Strong knowledge of and experience with database querying (SQL).
  • Knowledge of statistics and experience using statistical packages for analyzing datasets, especially Excel.
  • Practical experience with any of the following tools: Tableau, Relational databases, big data, Salesforce, Python, R, Programming (ETL frameworks)

How to prepare for your Amazon data analyst interview

Your preparation should primarily be surrounding the 16 leadership principles, SQL queries, and database management.

For your final round, you’ll have a sequence of 4-5 rounds of interviews. Expect 1-2 technical interviews and 2-3 behavioral interviews.

Common onsite Amazon data analyst SQL question:

Amazon/AWS SQL Interview Question 49: Bids from yesterday
Prompt: Find how many bids were yesterday. Please note that for this problem we are assuming that today is 2022-01-19.

Table: bids
+------+-----------+--------------------+-------+--------------+
|bid_id|customer_id| order_datetime     |item_id|order_quantity|
+------+-----------+--------------------+-------+--------------+
|A-001 |32483      |2021-12-15 09:15:22 |B000   |3             |
|A-002 |21456      |2022-01-10 09:28:35 |B001   |1             |
|A-003 |21456      |2022-01-09 09:28:35 |B005   |1             |
|A-004 |42491      |2022-01-16 02:52:07 |B008   |2             |
|A-005 |42491      |2022-01-18 02:52:07 |B008   |2             |
|A-006 |42491      |2022-01-18 02:52:07 |B008   |5             |
|A-007 |21456      |2022-01-17 09:28:35 |B000   |1             |
|A-008 |21456      |2022-01-17 10:28:35 |B008   |3             |
|A-009 |21456      |2022-01-19 10:28:35 |B000   |2             |
+------+-----------+--------------------+-------+--------------+

Solution

select
    count(bid_id)
from bids
where order_datetime::date = '2022-01-18'::date;

Amazon Data Scientist Interview Questions

Landing an interview with Amazon is an exciting opportunity, but it can also be nerve-wracking. The interview process can be rigorous, but with the right preparation, you can make a strong impression and increase your chances of landing the job. In this section, we’ll walk you through the three rounds of the Amazon Data Science interview process and provide tips on how to prepare and succeed.

Interview format for a data scientist role at Amazon

  • Round 1: Phone screen
  • Round 2: Technical interview
  • Round 2B: Technical interview*
  • Round 3: Onsite (final round)

* Some candidates have up to 2 technical screenings before the onsite.

The data scientist interview at Amazon will touch on more complex topics such as machine learning, algorithms, or designing predictive modeling processes that handle complex data.

Similar to the data analyst you’ll need to potentially know statistics, SQL, R, and Python.

As a data science professional, it is essential to have an in-depth understanding of SQL and database management skills. An interview for a data science position at Amazon requires a robust and refined SQL knowledge base. In this article, we will be exploring the Amazon data science interview process, which includes three rounds of assessments, specifically designed to test your SQL proficiency and how you would use it in a real-life scenario.

Round 1: Amazon Online Assessment

The first round of the Amazon data science interview is an online assessment. The test contains a set of SQL questions designed to assess your understanding of the language. You will be given a database and a set of problems that you need to solve using SQL. The questions will cover basic concepts like SQL queries, aggregate functions, join operations, and data manipulation. The key to acing this round is to have a strong foundation in SQL and to be able to quickly and accurately translate the problems into working SQL code.

To get yourself prepared for the online assessment, it’s essential to have a solid understanding of SQL. You can brush up your skills by visiting app.bigtechinterviews.com and practicing real SQL interview questions. The site offers a comprehensive database of SQL questions from past Amazon interviews, which will help you understand the type of questions you can expect in the online assessment.

Round 2: Technical Phone Interview

The second round of the Amazon data science interview is a technical phone interview. During this round, you will be asked to explain your SQL solutions from the online assessment and your approach to solving them. Additionally, you will be asked to write SQL code on the spot to solve a problem related to the data science field. This round tests your ability to think on your feet and apply your SQL knowledge to real-life scenarios.

Onsite Interview:

The final round of the Amazon data science interview is an onsite interview. During this round, you will be asked to complete a hands-on project using SQL. You will be given a dataset and a set of problems to solve using SQL. This round is designed to test your ability to apply your SQL knowledge to real-life scenarios and evaluate how well you can work with large datasets.

It’s crucial to be comfortable with working with large datasets and to have a solid understanding of SQL. You can prepare for this round by visiting app.bigtechinterviews.com and practicing real SQL interview questions. This will help you get a feel for the type of problems you might encounter during the onsite interview and build your confidence in applying your SQL knowledge to real-life scenarios.

How to prepare for your Amazon data scientist interview

Brush up on your window functions, practice the different types of statistical analysis in whichever language you are most comfortable with. Make sure to practice doing time series analysis and data manipulation surrounding dates and times.

Finally, behavioral questions require you to answer honestly and straight to the point; thus, ensure that you go through your resume multiple times and properly know what you have written in it.

Your preparation should primarily be surrounding the 16 leadership principles, SQL queries, and database management.

For your final round, you’ll have a sequence of 4-5 rounds of interviews. Expect 1-2 technical interviews and 2-3 behavioral interviews.

Behavioral Questions:

1. Can you describe a time when you had to handle a difficult situation with a co-worker?

Answer: I recall a situation where I was working on a project with a team member who had different ideas and opinions on how to approach the project. I scheduled a meeting with both of us to discuss the issue and find a solution that would satisfy both parties. We were able to come to a compromise and complete the project successfully.

2. Can you tell us about a time when you had to step out of your comfort zone to complete a task?

Answer: I remember a project that required me to present my findings to a large group of stakeholders, including executives. Although public speaking is not my strong suit, I recognized the importance of the task and prepared thoroughly for the presentation. The feedback I received was positive, and I was able to effectively communicate my findings to the stakeholders.

3. Can you walk us through a time when you had to work under tight deadlines?

Answer: I once had to analyze and present data for a client who required the results within a week. I prioritized my tasks and worked extra hours to ensure that I met the deadline. I also communicated regularly with my team to keep them informed of my progress and sought their assistance when necessary. As a result, I was able to deliver the results on time and received positive feedback from the client.

Read More: Amazon Data Engineer Interview Questions

Technical Questions:

1. Can you explain the difference between a primary key and a foreign key?

Answer: A primary key is a unique identifier for each record in a table. It ensures that each record has a unique identifier and cannot have a null value. On the other hand, a foreign key is a field in one table that refers to the primary key in another table. It establishes a relationship between two tables and ensures referential integrity.

2. Can you explain the purpose of an index in a database?

Answer: An index is a database object that allows for faster retrieval of data from a table. It works by creating a copy of the data and storing it in a structure that enables quick searching. The purpose of an index is to increase the speed of data retrieval operations and improve database performance.

3. Can you describe the difference between a left join and a right join in SQL?

Answer: A left join returns all the records from the left table and the matching records from the right table. If there are no matching records in the right table, the result will contain NULL values. On the other hand, a right join returns all the records from the right table and the matching records from the left table. If there are no matching records in the left table, the result will contain NULL values.

Most common responsibilities of a Data Scientist

  • Research and implement statistical and ML ing techniques (e.g. Bayesian s, NLP, graph networks, optimization methods) to different applications in talent decision making
  • Providing technical/science leadership, collaborative research, and creative problem solving to drive continued scientific innovation
  • Prototype and implement highly innovative learning algorithms and prediction techniques
  • Work closely with & software engineering teams to build implementations and integrated algorithms in production systems at a very large scale
  • Constructively critique peer research and mentor juniors and engineers
  • Presenting results, reports, and insights to both technical and business leadership

Example of data science SQL question

SQL Question: Write a query to return the product groups in the US that have no sales of any unit.

How To Streamline Your Preparation for Amazon SQL Interviews

Preparing for an Amazon SQL interview can be a daunting task, especially if you’re new to the field or have minimal experience. However, with proper planning and practice utilizing a SQL playground, you can ace your interview and land your dream job at Amazon.

Here are some tips to help streamline your preparation:

  1. Understand the Basics: Before diving into complex concepts, ensure that you have a thorough understanding of the basic SQL commands such as SELECT, FROM, WHERE, and ORDER BY. Familiarize yourself with common data types and their corresponding functions.
  2. Practice Data Manipulation: Amazon SQL interviews often test your ability to manipulate large datasets effectively. Practice writing queries on sample datasets to improve your skills in data manipulation.
  3. Brush Up on Joins: Joins are an integral part of SQL and a common topic in Amazon interviews. Brush up on different types of joins, such as INNER JOIN, LEFT JOIN, and RIGHT JOIN, and practice writing queries that involve joins.
  4. Know the Company Culture: Researching the company culture at Amazon can give you an edge during your interview. Familiarize yourself with the company’s values, goals, and mission to align your responses with their expectations.
  5. Take Practice Tests: Practice makes perfect, and taking mock interviews can help you assess your skills and identify areas for improvement. There are many online resources available that offer practice tests specifically tailored for Amazon SQL interviews.
  6. Stay Calm and Confident: Finally, remember to stay calm and confident during your interview. Take deep breaths, maintain good posture, and focus on providing clear and concise responses to the interviewer’s questions.

By following these tips and practicing regularly, you can boost your chances of success in an Amazon SQL interview. Remember to research the company beforehand and consider practicing more Amazon SQL questions, have a good understanding of SQL basics, and practice writing complex queries to impress you.

Bonus Amazon SQL Interview Questions

1. Find the second earliest bid

The second Amazon SQL Interview question is an interesting one. It invites us to identify the second earliest bid from a dataset. This kind of query not only tests your ability to manipulate date and time data types but also your understanding of sorting & ranking functions. It’s a practical problem, mimicking the kind of analysis you may need to run when evaluating bids in a real-world business scenario.

Write a query to find the second earliest bid for each customer on the day they place 2 or more bids on the same day. Please return the customer ID, order date time, and second bid ID.

Note: For this problem, we are assuming that today is 2022-01-19

Example Table:

Table: bids

+------+-----------+--------------------+-------+--------------+
|bid_id|customer_id| order_datetime     |item_id|order_quantity|
+------+-----------+--------------------+-------+--------------+
|A-001 |32483      |2021-12-15 09:15:22 |B000   |3             |
|A-002 |21456      |2022-01-10 09:28:35 |B001   |1             |
|A-003 |21456      |2022-01-09 09:28:35 |B005   |1             |
|A-004 |42491      |2022-01-16 02:52:07 |B008   |2             |
|A-005 |42491      |2022-01-18 02:52:07 |B008   |2             |
|A-006 |42491      |2022-01-18 02:52:07 |B008   |5             |
|A-007 |21456      |2022-01-17 09:28:35 |B000   |1             |
|A-008 |21456      |2022-01-17 10:28:35 |B008   |3             |
|A-009 |21456      |2022-01-19 10:28:35 |B000   |2             |
+------+-----------+--------------------+-------+--------------+

Example Output:

+-----------+------------------------+----------+
|customer_id|order_datetime          |second_bid|
+-----------+------------------------+----------+
|21456      |2022-01-17T00:00:00.000Z|A-008     |
+-----------+------------------------+----------+

Want to find the second earliest bid yourself? You can by using our dynamic SQL engine.

amazon-sql-interview-question-find-second-bid

Amazon’s Second Earliest Bid Solution:

To solve this Amazon SQL interview question, our goal is to identify the second bid placed by each customer on any day they make at least two bids. To effectively do this, we will break it down into two main steps:

  • Step 1: Generate an ordered sequence for all bids placed by customers per day, disregarding the exact time.
SELECT customer_id, order_datetime::date, bid_id, RANK() OVER ( PARTITION BY customer_id, order_datetime::date  ORDER BY order_datetime ASC) AS order_seq FROM bids

Here’s what’s happening: We’re casting the ‘order_datetime’ to a date to omit the time. The `RANK()` function assigns an ascending order to all bids, resetting for each customer and each day – regardless of the precise order time.

  • Step 2: Using a Common Table Expression (CTE) to encapsulate Step 1, we can then identify and select the second bids placed by each customer on the days they made at least two bids.

Solution:

WITH ranked AS (
 SELECT 
 customer_id,
 order_datetime::date,
 bid_id,
 RANK() OVER (
 PARTITION BY customer_id, order_datetime::date 
 ORDER BY order_datetime ASC
 ) AS order_seq
 FROM bids
)

SELECT
customer_id,
order_datetime,
bid_id AS second_bid
FROM ranked
WHERE order_seq = 2

Our `WHERE` clause serves dual purposes. It not only selects the second bid of the day but also ensures that the selected day has at least two bids. This final query effectively provides the required list of second bids for each customer on the days they place at least two bids.

2. Find the buildings with no employees

The finance director wants to cut costs and asks you to write a query to return a list of buildings where there are no employees.

Note: For this problem, we are assuming that today is 2022-01-19

Example Table:

Table: employee

Table: employee
+------+----------+---------+----------+------+----+----------+-----------+
|emp_id|first_name|last_name|manager_id|salary|dept|start_date|building_id|
+------+----------+---------+----------+------+----+----------+-----------+
|1     |hector    |bush     |1         |40000 |ops |2018-03-05|1          |
|2     |kim       |stewart  |1         |31000 |eng |2019-04-05|2          |
|3     |peter     |thompson |1         |31700 |ds  |2019-02-05|3          |
|4     |thomas    |henderson|1         |32000 |ops |2018-03-05|2          |
|5     |john      |free     |1         |35000 |eng |2019-03-08|3          |
|6     |tara      |glad     |5         |32000 |ds  |2019-01-12|1          |
|7     |linda     |bruss    |5         |30000 |ops |2020-04-19|3          |
|8     |forest    |gump     |6         |29000 |eng |2021-04-19|1          |
|9     |luke      |smith    |7         |28000 |ds  |2019-06-24|2          |
+------+----------+---------+----------+------+----+----------+-----------+

Example Table:

Table: building

Table: employee
+------+----------+---------+----------+------+----+----------+-----------+
|emp_id|first_name|last_name|manager_id|salary|dept|start_date|building_id|
+------+----------+---------+----------+------+----+----------+-----------+
|1     |hector    |bush     |1         |40000 |ops |2018-03-05|1          |
|2     |kim       |stewart  |1         |31000 |eng |2019-04-05|2          |
|3     |peter     |thompson |1         |31700 |ds  |2019-02-05|3          |
|4     |thomas    |henderson|1         |32000 |ops |2018-03-05|2          |
|5     |john      |free     |1         |35000 |eng |2019-03-08|3          |
|6     |tara      |glad     |5         |32000 |ds  |2019-01-12|1          |
|7     |linda     |bruss    |5         |30000 |ops |2020-04-19|3          |
|8     |forest    |gump     |6         |29000 |eng |2021-04-19|1          |
|9     |luke      |smith    |7         |28000 |ds  |2019-06-24|2          |
+------+----------+---------+----------+------+----+----------+-----------+

Example Output:

+-----------+-------------+
|building_id|building_name|
+-----------+-------------+
|4          |ZS           |
+-----------+-------------+

Before we dive into the Amazon SQL question solution? Want to give it a shot and try and solve it yourself using our dynamic SQL engine? 

amazon-sql-interview-question-buildings-with-no-employees

Amazon’s No Employees in Building Solution:

To solve this Amazon SQL interview question, we’ll adopt a straightforward strategy instead of resorting to complex joins. The objective is to fetch all building details that are not associated with any employees. The logic behind this approach involves selecting all the ‘building_ids’ from the ‘building’ table that are not present in the ’employee’ table. Here’s how we can achieve this:

SELECT 
building_id, 
building_name 
FROM building 
WHERE building_id NOT IN (SELECT building_id FROM employee)

To understand what this query does, let’s break it down. The ‘SELECT’ statement fetches ‘building_id’ and ‘building_name’ from the ‘building’ table. The ‘WHERE’ clause excludes the ‘building_id’ entries that are present in the ’employee’ table. Hence, the query returns a list of buildings that do not house any employees.

3. What’s the difference between dense_rank() and row_number?

Both `dense_rank()` and `row_number()` are window functions used to generate sequential numbers for the rows in a given dataset. However, there are some key differences between them:

  • Generation of sequential numbers: The main difference between these two functions is that `row_number()` generates unique consecutive numbers for each row in the dataset, while `dense_rank()` ensures that
  • Skipping over duplicate values: The `dense_rank()` function also assigns sequential numbers to rows in a dataset, but it does so while skipping over any duplicate values. This means that if there are two or more identical records, they will receive the same sequential number as the previous unique value.
  • Ordering of rows: In both cases, the sequential numbers generated by these functions depend on the order in which they are applied. However, `row_number()` can generate different numbers if the ordering of rows changes, while `dense_rank()` will always assign the same sequential numbers as long as the order remains constant.
  • Partitioning: Both functions also have an optional OVER clause that allows them to be partitioned by a specific column or set of columns. However, the way they handle partitioning is different. `row_number()` will assign sequential numbers based on the order within each partition, while `dense_rank()` will continue generating sequential numbers across partitions without resetting to 1.

In summary, both functions generate sequential numbers for rows in a dataset, but `dense_rank()` is better suited for cases where duplicates need to be handled and the order of rows is not important. On the other hand, `row_number()` should be used when unique sequential numbers are required and their generation is based on the ordering of rows.

Frequently Asked Questions (FAQ):

  • Question: What is the typical starting salary of an Amazon Analyst?
    • Ranges from $73k to $94k
  • Question: How many rounds is an Amazon business analyst interview?
    • 3-4 rounds. Usually, it follows this format, Phone screen > Technical assessment > Onsite.
  • Question: What are the skills and qualifications for an analyst at Amazon?
    • Bachelor’s degree in Business, Engineering or a related field
    • 2+ years of professional experience in analytics, business analysis, or comparable consumer analytics position
    • Advanced working knowledge of data mining using SQL, ETL, data warehouse as well as Excel
    • Demonstrated experience in preparing and executing presentations of technical and business level data
  • Question: What happens behind the scenes?
    • The hiring committee will reconvene and review the past cluster of interviews. This is when the bar raiser will be present to ensure the candidate that gets the offer is at minimum 50% better than the current staff at Amazon. During this meeting, the committee will also be deciding for the candidate that gets the offer what his/her level will be. After this step, there will potentially be a reference check, but that is typically for more senior-level roles.
  • What are Amazon’s 16 leadership principles?
    1. Customer Obsession: Leaders start with the customer and work backwards. They work vigorously to earn and keep customer trust. Although leaders pay attention to competitors, they obsess over customers. 
    2. Ownership: Leaders are owners. They think long term and don’t sacrifice long-term value for short-term results. They act on behalf of the entire company, beyond just their own team. They never say “that’s not my job.”
    3. Invent and Simplify: Leaders expect and require innovation and invention from their teams and always find ways to simplify. They are externally aware, look for new ideas from everywhere, and are not limited by “not invented here.” As we do new things, we accept that we may be misunderstood for long periods of time. 
    4. Right, A Lot: Leaders are right a lot. They have strong judgment and good instincts. They seek diverse perspectives and work to disconfirm their beliefs.
    5. Learn and Be Curious: Leaders are never done learning and always seek to improve themselves. They are curious about new possibilities and act to explore them.
    6. Hire and Develop the Best: Leaders raise the performance bar with every hire and promotion. They recognize exceptional talent, and willingly move them throughout the organization. Leaders develop leaders and take seriously their role in coaching others. We work on behalf of our people to invent mechanisms for development like Career Choice.
    7. Insist on the Highest Standards: Leaders have relentlessly high standards – many people may think these standards are unreasonably high. Leaders are continually raising the bar and drive their teams to deliver high quality products, services, and processes. Leaders ensure that defects do not get sent down the line and that problems are fixed so they stay fixed.
    8. Think Big: Thinking small is a self-fulfilling prophecy. Leaders create and communicate a bold direction that inspires results. They think differently and look around corners for ways to serve customers.
    9. Bias for Action: Speed matters in business. Many decisions and actions are reversible and do not need extensive study. We value calculated risk taking.
    10. Frugality: Accomplish more with less. Constraints breed resourcefulness, self-sufficiency, and invention. There are no extra points for growing headcount, budget size, or fixed expense.
    11. Earn Trust: Leaders listen attentively, speak candidly, and treat others respectfully. They are vocally self-critical, even when doing so is awkward or embarrassing. Leaders do not believe their or their team’s body odor smells of perfume. They benchmark themselves and their teams against the best.
    12. Dive Deep: Leaders operate at all levels, stay connected to the details, audit frequently, and are skeptical when metrics and anecdote differ. No task is beneath them.Right, A Lot: Leaders are right a lot. They have strong judgment and good instincts. They seek diverse perspectives and work to disconfirm their beliefs.
    13. Have Backbone; Disagree and Commit: Leaders are obligated to respectfully challenge decisions when they disagree, even when doing so is uncomfortable or exhausting. Leaders have conviction and are tenacious. They do not compromise for the sake of social cohesion. Once a decision is determined, they commit wholly.
    14. Leaders focus on the key inputs for their business and deliver them with the right quality and in a timely fashion. Despite setbacks, they rise to the occasion and never settle.
    15. Leaders work every day to create a safer, more productive, higher performing, more diverse, and more just work environment. They lead with empathy, have fun at work, and make it easy for others to have fun. Leaders ask themselves: Are my fellow employees growing? Are they empowered? Are they ready for what’s next? Leaders have a vision for and commitment to their employees’ personal success, whether that be at Amazon or elsewhere.
    16. Success and Scale Bring Broad Responsibility: We started in a garage, but we’re not there anymore. We are big, we impact the world, and we are far from perfect. We must be humble and thoughtful about even the secondary effects of our actions. Our local communities, planet, and future generations need us to be better every day. We must begin each day with a determination to make better, do better, and be better for our customers, our employees, our partners, and the world at large. And we must end every day knowing we can do even more tomorrow. Leaders create more than they consume and always leave things better than how they found them.
  • How do you prepare for an Amazon Business Intelligence Engineer Interview? 
Prepare for an Amazon Business Intelligence Engineer interview by aligning with Amazon’s Leadership Principles, mastering SQL interview questions and analytics tools, understanding basic machine learning, and practicing behavioral and case study questions. Practice for your interview using SQL playgrounds, research Amazon’s BI solutions, stay updated on industry trends, and showcase your problem-solving skills.

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