Amazon Interview Questions By Scholarhat.pdf

Amazon Interview Questions By Scholarhat.pdf

1. Cracking the Amazon Interview: Essential Questions and
Tips
Amazon Interview Questions
Getting ready for an Amazon Interview Questions? This guide provides you with necessary Amazon interview questions to
help you feel prepared and confident. We've included Amazon interview questions for freshers with answers, as well as
insights on how to respond to technical and culture-fit questions, as well as expert advice on how to reply to Amazon
interview questions with impactful replies. Prepare for success and perform well during your interview!
Behavioral questions: Share examples of challenges you've faced or how you've taken ownership of a project. Focus on
leadership qualities.
Technical questions: If you're applying for a technical role, expect coding problems involving algorithms, data
structures, and system design. You'll likely solve these on a coding platform or whiteboard.
Problem-solving skills: Be prepared to show how you break down complex problems and find efficient solutions. You
may face real-world scenarios.
Amazon's Management Principles: Expect questions about Amazon's ideals, such as customer focus, ownership, and
streamlining procedures.
This Interview Tutorial will help you to complete information on theAmazon Interview Process, Common HR Interview
Questions, Amazon Interview Questions for Freshers, Amazon Behavioral Interview Questions, Amazon Developer
Interview Questions, Amazon Interview SQL Questions, Amazon System Design Interview Questions, and a lot more.
What should you expect in Amazon Interviews?

2. Stage
Eligibility Criteria
Interview Rounds
Online Application
Recruitment Process
Let us understand the Azazon Interview Process in detail:
Initial screening via phone or online assessment for coding skills.
If successful, further rounds will be scheduled, including technical and
behavioral interviews.
Submit your resume and application through Amazon's career portal.
Ensure the resume highlights key skills like coding, problem-solving, and relevant
projects.
Phone Screen: A short discussion to evaluate basic technical and behavioral
knowledge.
Technical Interviews: Usually 2-3 rounds involving coding, algorithms, and
problem-solving.
HR Interview: To assess cultural fit, motivation, and role-specific interests.
Description
A Bachelor's or Master's degree in relevant fields (e.g., Computer Science,
Engineering).
Strong academic record, often with a good GPA (varies by role and location).
Relevant skills or experience, such as internships for freshers or prior work
experience for senior roles.
Coding and algorithm: Practice problem-solving with arrays, linked lists, trees, sorting, searching, and dynamic
programming.
Communication: Be clear about your thought process and approach to problem resolution.
Cultural fit: Amazon promotes a fast-paced work atmosphere, so be prepared to talk about how you handle stress and
uncer tainty.
Role-specific questions: Questions will be matched to your specific position (software engineer, product manager, or
data scientist).
Understanding the Amazon Interview Process

3. Technical
(Freshers)
HR Interview Question
Interview Questions
Technical
(Experienced)
Interview Questions
Tell me about yourself.
Why do you want to work at Amazon?
What is your biggest strength/weakness?
Tell me about a time when you faced a challenge at work.
Where do you see yourself in 5 years?
While answering this question, be honest, but focus on a weakness you are actively working to improve.
Advanced topics in data structures, algorithms, and system design.
Questions might cover complex problem-solving scenarios, optimization, and
real-world applications.
Expect discussions on past projects, architecture decisions, and coding
challenges you’ve faced.
Choose a strength that is relevant to the job you're applying for and provide an example to back it up.
Example: "My biggest strength is my problem-solving ability. For example, in my last project, I solved a complex issue with a
database by optimizing its queries, which resulted in a 30% performance improvement."
Show that you have researched Amazon and align its values with your career goals.
Example: "I admire Amazon’s commitment to customer obsession and its ability to innovate constantly. I believe my
passion for problem-solving and working in fast-paced environments aligns well with Amazon’s culture."
Focus on basic data structures (arrays in data structure, linked lists in data
structure, stacks in data structure).
Problem-solving questions related to algorithms (Sorting in Data Structures,
Searching in Data Structures, etc.)
It may include simple system design problems or questions that test logic and
reasoning.
You have a strong background in software development, with experience in coding and problem-solving, and you are excited
about this role at Amazon because you value innovation and the opportunity to work on impactful projects.
Example: "I am a Computer Science graduate with a strong passion for coding and problem-solving. During my internship at
XYZ Company, I worked on developing a web app, which sparked my interest in full-stack development. I am excited about
the opportunity at Amazon because of its innovative culture and global impact."
Common HR Interview Questions
Q 1. Tell me about yourself.
Q 2. Why do you want to work at Amazon?
Q 3. What would you say is your biggest strength?
Q 4. What would you say is your biggest weakness?

4. Focus on a specific challenge, how you handled it, and the outcome.
Example: "During my internship, I was tasked with debugging a major issue in the system. I collaborated with the team to
identify the root cause, fixed the bug, and improved system stability by 25%."
Be positive, focusing on the opportunity for growth and learning.
Example: "I left my last internship because I felt I had learned a lot, and I was ready to take on new challenges. I am looking
for a role where I can further develop my skills and contribute to exciting projects."
Focus on a situation where you led a project or team, even in a small way.
Example: "During a group project at university, I took the lead in organizing tasks and ensuring the project was completed on
time. My leadership helped the team stay focused and finish ahead of schedule."
Show that you can stay organized, maintain a positive attitude, and prioritize tasks effectively.
Example: "I stay calm under pressure by breaking down tasks into smaller parts and focusing on one thing at a time. In my
last internship, I was able to meet deadlines during a high-pressure project by managing my time efficiently."
Example: "I tend to be a perfectionist, which can slow me down sometimes. However, I have been working on managing my
time better and focusing on delivering high-quality work within deadlines."
Discuss how you assess tasks based on urgency and importance using time management strategies.
Example: "I prioritize tasks based on their deadlines and impact. I use tools like to-do lists and project management
software to stay organized and ensure everything gets done on time."
Talk about growth and leadership within the company.
Example: "In 5 years, I see myself growing as a software engineer, taking on more responsibility, and contributing to high-
impact projects. I hope to be part of a team that drives innovation at Amazon."
Q 10. How do you prioritize tasks?
Q 7. Where do you see yourself in 5 years?
Q 9. How do you handle pressure and stress?
Q 6. Why did you leave your last job/internship?
Q 8. Can you describe a time when you showed leadership?
Q 5. Can you tell me about a time when you faced a challenge at work?
Amazon Interview Questions for Freshers
Q 11. Why do you want to work at Amazon?

5. This question tests your teamwork skills. Describe a situation where you worked with others and what you contributed to
the team.
Example: "In a group project at college, we were tasked with building a web application. I took on the role of managing the
database and backend while coordinating with the front-end developers to ensure everything integrated smoothly."
They want to know how you approach unknown situations. Explain how you'd research, ask for help, or find a solution on
your own.
Example: "If I don't know the answer to a problem, I first try to break it down into smaller parts. If I’m still stuck, I’ll look for
solutions online, check documentation, or ask a colleague for help. For instance, during a coding challenge, I referred to
StackOverflow and learned a new solution."
This question helps Amazon understand why you're interested in their company. Talk about what excites you about
Amazon's work culture, innovation, or values.
Example: "I admire Amazon's customer-obsessed culture and its ability to constantly innovate. The chance to contribute to
a company that always strives for excellence and disrupts industries excites me, and I want to be part of that change."
Amazon values time management. Share how you decide which tasks are most important and how you manage your time
effectively.
Example: "When I have multiple deadlines, I prioritize tasks by urgency and importance. For example, during my internship, I
had to submit a report and also work on a product feature. I focused on completing the report first since it had a tighter
deadline, then dedicated time to the product feature."
They want to see your problem-solving skills. Explain a real-life challenge, how you approached it, and the result.
Example: "During my final project, I faced a challenge when my team’s server went down just before our presentation. I
quickly coordinated with my team to troubleshoot, and we worked together to get the server back up in time for the demo,
preventing any delays."
Amazon looks for candidates who align with their principles. Briefly mention key principles like customer obsession,
ownership, or inventing and simplifying.
Example: "I know that Amazon values principles like customer obsession and ownership. For instance, the principle of
'Customer Obsession' means understanding customers' needs and working to exceed their expectations. I always try to
Q 16. What do you know about Amazon’s leadership principles?
Q 12. Can you describe a challenging situation and how you handled it?
Q 14. Tell us about a time you worked in a team. What role did you play?
Q 13. How do you prioritize your tasks when you have multiple deadlines?
Q 15. How would you handle a situation where you don’t know the answer to a
problem?

6. understand customer feedback to improve my work."
Here, we have provided you with some of the most important questions Amazon Behavioral Interview Questions.
This tests your communication skills. Pick a technical concept you know well and explain it simply.
Example: "If I had to explain 'Cloud Computing' to someone, I would say, 'It’s like using services such as Google Drive or
Dropbox. Instead of storing files on your computer, you store them on the internet, where they’re easily accessible from
anywhere.'
Be honest, but focus on strengths that are relevant to the role. For weaknesses, mention something you're actively working
on improving.
Example: "One of my strengths is my ability to learn quickly and apply new technologies. However, I’ve noticed that
sometimes I focus too much on small details, and I am working on improving my time management to balance precision
with efficiency."
Explain your method for staying organized, whether it’s using tools, making lists, or breaking down tasks into smaller parts.
Example: "I use tools like Trello and Google Calendar to stay organized. For example, when managing multiple assignments,
I break each project into smaller tasks and set deadlines for each task to ensure I stay on track."
This question tests conflict resolution. Share an example where you disagreed but handled it professionally to reach a
solution.
Example: "In one project, a team member and I disagreed on the approach to a feature. I listened to their point of view,
explained mine, and we found a compromise by incorporating parts of both ideas, which improved the final product."
Q 18. What are your strengths and weaknesses?
Q 19. How do you stay organized when working on multiple projects?
Q 20. Have you ever disagreed with a team member? How did you resolve it?
Q 17. Can you explain a technical concept to someone who doesn’t understand it?
Amazon Behavioral Interview Questions
Q 21. Tell me about a time when you took a risk at work. What was the outcome?
Q 22. Tell me about a time when you disagreed with a supervisor or manager. How did you handle it?
Q 23. Give me an example of a time you showed initiative.
Q 24. Tell me about a time you failed. How did you handle it?
Q 25. Describe a time when you had to manage conflicting priorities. How did you handle it?
Q 26. Tell me about a time when you worked on a team project. What was your role, and how did you
contribute?

7. Q 27. Can you describe a situation where you had to manage multiple tasks under tight deadlines?
Q 28. Tell me about a time when you had to overcome a difficult challenge at work.
Q 29. Describe a situation where you had to make a tough decision. What was the outcome?
Q 30. Tell me about a time when you had to deal with an unhappy customer. How did you resolve the
situation?
Q 31. Can you give an example of a time when you had to adapt to a new process or technology?
Q 32. Describe a time when you worked under pressure. How did you manage it?
Q 33. Tell me about a time when you contributed to a project that was outside of your comfort zone.
Q 34. Can you describe a situation where you had to persuade others to adopt your point of view?
Q 35. Tell me about a time you showed leadership without having formal authority.
Q 36. Tell me about a time when you had to quickly learn something new. How did you approach it?
Q 37. Describe a situation where you had to make a decision without all the necessary information. How
did you handle it?
Q 38. Tell me about a time when you had to work with someone who was difficult. How did you manage
the situation?
Q 39. Tell me about a time when you helped someone improve their performance or skills.
Q 40. Can you describe a time when you had to juggle multiple projects? How did you manage them?
The major difference between Stack in Data Structure and Queue in Data Structure:
By practicing these questions, you can easily make a better path for Amazon's journey.
Feature
Data
Type
Operations
Stack in Data Structure
LIFO (Last In, First Out)
Queue in Data Structure
FIFO (First In, First Out)
Structure
Push (add) and Pop (remove) at the top
only
Undo
Enqueue (add) at the rear and Dequeue (remove) from
the front
Task scheduling, customer service lines
Example
Cases
Use functionality, call stack in
programming
Hash Table in Data Structures stores key-value pairs, making it easy to find, add, or remove data quickly. Here's how it works
in simple terms:
Amazon Software Developer Interview Questions
Q 41. What is the difference between a stack and a queue?
Q 42. What is a hash table, and how does it work?

8. A shallow copy copies references to the objects, while a deep copy copies the objects themselves recursively.
To reverse a linked list in Data Structure, change the next pointers of the nodes so they point to the previous node.
In this code, the function traverses the linked list and reverses the direction of the pointers to create a reversed list.
Q 45. What is the difference between a deep copy and a shallow copy?
Binary search in Data Structure operates in O(log n) time complexity, where n is the number of elements in a sorted array.
Polymorphismisobject-oriented programming concepts thatallow different classes to provide a common interface while
implementing their own version of methods.
In this case, the shallow copy will copy the outer list but reference the inner list, while the deep copy will copy both the outer
and inner lists.
Q 46. Explain the concept of polymorphism in object-oriented programming.
Each item has a unique "key" (like a label) and a "value" (the data you want to store).
A hash function takes the key and converts it into a specific index in an array where the value will be stored.
When you need to find the data, the hash function uses the key again to quickly locate the correct spot.
If two keys produce the same index (a "collision"), the hash table has a way to handle this, like using a linked list or
reassigning it to a different spot.
Q 44. How do you reverse a linked list?
Q 43. What is the time complexity of binary search?
Sample Code
Sample Code
import copy
Sample Code
class Shape:
def draw(self):
def reverse_linked_list(head):








prev = None
current = head
while current:
next_node = current.next
current.next = prev
prev = current
current = next_node
return prev
original = [1, [2, 3]]
shallow_copy = copy.copy(original)
deep_copy = copy.deepcopy(original)

9. pass
class Circle(Shape):


def draw(self):
print("Drawing a circle")
class Rectangle(Shape):


def draw(self):
print("Drawing a rectangle")
final int MAX_SIZE = 100; // MAX_SIZE cannot be reassigned
The time complexity of bubble sort in data structure is O(n^2), where n is the number of elements.
In this example, polymorphism allows different shapes to implement their own version of the drawing method.
Q 47. What is a binary tree, and how does it differ from a binary search tree?
A binary tree in the data structurewhere each node has at most two children, while a Binary Search Tree in Data
Structuresis a binary tree where the left child is smaller and the right child is larger than the parent node.
A linked list is a linear data structure where each element points to the next element, whereas an array stores elements in
contiguous memory locations.
The final keyword can be applied to variables, methods, and classes. It indicates that the value of a variable cannot be
changed, a method cannot be overridden, and a class cannot be subclassed.
Read More: What is Exception Handling in Java?: try, catch, throw, finally
A binary tree is a tree structure where each node can have up to two child nodes (left and right), but there are no specific
rules about the order of the nodes.
A binary search tree (BST) is a specific type of binary tree with an added rule: for each node, the left child node's value
must be smaller, and the right child node's value must be larger. This ordering allows faster searching, inserting, and
deleting of values.
In a binary tree, node values can be in any order, while in a BST, nodes are organized to support efficient data lookup.
An LRU cache is typically implemented using a hash map (for fast access) and a doubly linked list (for maintaining the order
of access). Example: When the cache reaches its limit, the least recently used element is removed. For example, in a web
browser, the most recently accessed pages are kept in memory, and the least recently accessed ones are removed when the
cache is full.
Q 50. What is the time complexity of bubble sort?
Q 51. What is the purpose of the ‘final’ keyword in Java?
Q 49. What is a linked list, and how does it differ from an array?
Q 48. How do you implement an LRU (Least Recently Used) cache?
Sample Code

10. Q 52. What is the difference between an abstract class and an interface in object-
oriented programming?
An abstract class can provide both abstract methods and concrete methods, while an interface can only define abstract
methods (unless default methods are used in languages like Java).
A race condition occurs when two or more threads access shared data and try to change it at the same time. The outcome
depends on the sequence in which the threads execute.
Also Consider: Multithreading in Java
A deadlock occurs when two or more threads are blocked forever, each waiting on the other to release a resource. It can be
prevented by using proper locking mechanisms and avoiding circular dependencies.
Quick Sort Algorithm in Data Structures is a divide-and-conquer algorithm that selects a pivot element and partitions the
array around it. The time complexity is O(n log n) on average, but O(n^2) in the worst case.
Memory leaks in Java can be avoided by ensuring that unused objects are dereferenced and garbage collection occurs
properly.
A priority queue in the data structure is a data structure where each element has a priority, and the element with the highest
priority is served before other elements.
Exception handling allows you to manage errors or exceptional conditions that occur during program execution without
crashing the program. In Java, the try-catch block allows you to catch and handle exceptions like file not found, database
connection errors, etc.
The `==` operator compares references (whether two objects point to the same memory location), while `equals()`
compares the actual content or values of the objects.
Q 58. How do you implement a priority queue?
Q 59. How do you avoid memory leaks in Java?
Q 57. What is a race condition in multi-threading?
Q 54. What is the difference between `==` and `equals()` in Java?
Q 56. What is the purpose of exception handling in programming?
Q 60. What is the difference between `throw` and `throws` in Java?
Q 53. How does a quicksort algorithm work, and what is its time complexity?
Q 55. What is a deadlock in a multi-threaded application, and how do you prevent it?

11. Static methods belong to the class itself, while non-static methods belong to instances of the class.
A static method can be called without creating an instance of the class, whereas a non-static method requires an object to
be invoked:
In the following code, the `Singleton` class ensures that only one instance of the class is created, and it can be accessed
through the ̀`getInstance()` method:
ArrayList in Java uses a dynamic array to store elements and provides fast random access but slower insertions and
deletions. A LinkedList in Javauses a doubly linked list and offers faster insertions and deletions but slower random
access.
The 'throw' keyword is used to explicitly throw an exception from a method or block of code, while throws is used in a
method signature to declare that the method may throw an exception.
The singleton design pattern ensures that a class has only one instance and provides a global point of access to that
instance.
Example
Example
Example
Example
class Singleton {








}
private static Singleton instance;
private Singleton() {}
public static Singleton getInstance() {
if (instance == null) {
instance = new Singleton();
}
return instance;
}
throw new IllegalArgumentException("Invalid argument");
class MyClass {


}
static void staticMethod() { System.out.println("Static method"); } void
nonStaticMethod() { System.out.println("Non-static method"); }
Q 61. What is a singleton pattern in object-oriented design?
Q 62. What is the difference between static and non-static methods?
Q 63. What is the difference between `ArrayList` and `LinkedList` in Java?

12. A class is a blueprint for creating objects, while an object is an instance of a class.
In Java, a class ̀`Dog` can inherit from a class ̀`Animal` to reuse its methods like ̀`bark()`:
A constructor in Java is a special method used to initialize objects of a class. It is called when an object is created.
If `Car` is a class, then an object of that class would be a specific car like `myCar = new Car();` which creates an instance of
the ̀`Car` class.
Inheritance in object-oriented programming allows a class to acquire the properties and behaviors of another class. It
promotes code reusability and hierarchical relationships.
Use an `ArrayList` when you need fast lookups by index, and use a `LinkedList` when you frequently add or remove elements.
For example, an `ArrayList` might be used to store a list of names, and a `LinkedList` might be used to implement a queue
where elements are added and removed frequently.
A constructor with no parameters initializes the object with default values, while a constructor with parameters initializes it
with custom values. For example:
In this example, `Dog` inherits from `Animal` and can use the `sleep()` method from `Animal` while adding its own method,
`bark().`
Q 64. What is the difference between a class and an object?
Q 66. What is a constructor in Java, and what is its purpose?
Q 65. Explain the concept of inheritance in object-oriented programming.
Example
Example
Sample Code
class Car {




}
String color;
Car(String color) {
this.color = color;
}
Car myCar = new Car("Red");
class Dog extends Animal {

}
void bark() { System.out.println("Dog barks"); }
class Animal {

}
void sleep() { System.out.println("Animal sleeps"); }

13. This constructor assigns the value "Red" to the ̀`color` attribute of the ̀`Car` object.
In this case, the ̀`MathUtil` class cannot be extended, and no subclass can modify its behavior.
An annotation like ̀`@Override` tells the compiler that a method is intended to override a method in the superclass:
Multithreading in Java is a process of executing multiple threads concurrently to improve performance by performing
multiple operations simultaneously.
A web server might use multithreading to handle multiple client requests at the same time, creating a new thread for each
request to avoid blocking other operations.
Java annotations provide metadata about a program but do not affect its execution. They are often used to provide
information to the compiler or at runtime.
Interfaces define a contract for classes to implement, while abstract classes can provide both abstract and concrete
methods.
A final class cannot be subclassed. This is useful when you want to prevent inheritance and ensure the class's behavior is
not altered.
In this case, the ̀`@Override` annotation helps to ensure that the method correctly overrides a method from the parent class.
Amazon Interview SQL Database Questions
Q 68. What is the purpose of a `final` class in Java?
Q 69. What is multithreading in Java, and why is it used?
Q 70. What are Java annotations, and how are they used?
Q 67. What is the difference between an interface and an abstract class?
Example
Example
Example
@Override
public void run() {

}
System.out.println("Running");
final class MathUtil {



}
public static int add(int a, int b) {
return a + b;
}

14. Q 75. What is a `Subquery` in SQL?
A subquery is a query nested inside another query. It can be used to retrieve data that will be used in the outer query.
Q 74. What are aggregate functions in SQL?
Aggregate functions perform a calculation on a set of values and return a single result. Common aggregate functions
include:
Q 72. What is a `GROUP BY` clause, and how does it work?
The GROUP BY clause groups rows that have the same values into summary rows, like finding the total or average of a
column.
Q 73. What is the difference between `HAVING` and `WHERE`?
Q 71. What is the difference between `INNER JOIN` and `OUTER JOIN`?
INNER JOIN in SQL returns only the rows where there is a match in both tables. While 'OUTER JOIN in SQL' returns rows
even if there is no match in one of the tables.
WHERE filters rows before grouping.
HAVING filters groups after grouping.
Types of OUTER JOIN include:
LEFT OUTER JOIN: returns all rows from the left table and matching rows from the right table.
RIGHT OUTER JOIN: returns all rows from the right table and matching rows from the left table.
FULL OUTER JOIN: returns rows when there is a match in either the left or right table.
COUNT()
SUM()
AVG()
MIN()
MAX()
Example
Example
Example



SELECT product_id, SUM(sales)
FROM sales
GROUP BY product_id;




SELECT product_id, SUM(sales)
FROM sales
GROUP BY product_id
HAVING SUM(sales) > 1000;

15. SELECT city FROM customers
UNION
SELECT city FROM suppliers;

CREATE INDEX idx_customer_name ON customers (customer_name);

SELECT employee_id, employee_name


FROM employees
WHERE department_id = (SELECT department_id FROM departments WHERE department_name = 'Sales');
Q 77. What is the purpose of `INDEX` in SQL?
An index is used to speed up the retrieval of data. It improves query performance, especially for SELECT queries, but can
slow down INSERT, UPDATE, and DELETE operations.
Q 81. What is `TRUNCATE` and `DELETE` in SQL?
Q 80. What is Denormalization, and why is it used?
Denormalization is the process of combining tables to reduce the complexity of queries. It can improve performance by
reducing the need for multiple joins but may introduce data redundancy.
Q 79. What is Normalization, and why is it important?
Normalization in SQL is the process of organizing data in a database to reduce redundancy and improve data integrity. The
main levels of normalization are:
Q 78. What are the PRIMARY KEY and FOREIGN KEY?
The PRIMARY KEY and FOREIGN KEY are:
Q 76. What is the difference between `UNION` and `UNION ALL`?
UNION combines the results of two queries and removes duplicates.
UNION ALL combines the results of two queries and does not remove duplicates.
TRUNCATE removes all rows from a table but keeps the structure for future use. It is faster and cannot be rolled back.
PRIMARY KEY uniquely identifies each record in a table. It does not allow NULL values.
FOREIGN KEY is a field in one table that uniquely identifies a row of another table, creating a relationship between
tables.
Example:
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
Example

16. The CASE statement is used to add conditional logic in SQL queries.
The LIMIT clause is used to specify the number of records to return from a query.
DELETE removes rows based on a condition and can be rolled back if used in a transaction.
A VIEW in SQL is a virtual table that consists of a stored query. It can be used to simplify complex queries, and data can be
retrieved from views just like a regular table.
AUTO_INCREMENT is used to automatically generate a unique number for a column when a new record is inserted. It is
commonly used for primary keys.
Q 85. What is `LIMIT` in SQL?
Q 84. What is a `VIEW` in SQL?
Q 82. What is `AUTO_INCREMENT` in SQL?
Q 83. Explain the `CASE` statement in SQL.
Example
Example
Example
Example


SELECT * FROM employees
LIMIT 5;




CREATE TABLE users (
user_id INT AUTO_INCREMENT PRIMARY KEY,
username VARCHAR(50)
);


SELECT employee_name,
CASE
WHEN salary > 50000 THEN 'High'
WHEN salary > 30000 THEN 'Medium'
ELSE 'Low'




END AS salary_range
FROM employees;




CREATE VIEW employee_details AS
SELECT employee_id, employee_name, department_name
FROM employees
JOIN departments ON employees.department_id = departments.department_id;
Amazon System Design Interview Questions

17. Q 89. Design a Rate Limiter.
Description: Implement a system that restricts the number of API requests a user can make within a time period to avoid
overloading servers.
Q 93. Design a voting system
Description: Build a system where users can cast votes on topics. It should prevent multiple votes from the same user and
ensure real-time updates.
Q 91. Design a distributed cache system
Description: Create a cache that stores frequently accessed data to reduce database load and increase performance using
systems like Redis or Memcached.
Q 92. Design a distributed logging system
Description: Implement a centralized logging system to collect and store logs from various servers for monitoring and
troubleshooting using tools like ELK stack.
Q 86. Design a URL shortening service like Bit.ly
Description: Create a service that converts long URLs into short ones. Focus on unique URL generation, database storage,
and handling large-scale user requests.
Q 87. Design a messaging system like WhatsApp.
Description: Build a real-time messaging service that allows users to send text, images, and media. Ensure scalability, push
notifications, and message delivery.
Q 88. Design a scalable file storage system (like Google Drive).
Description: Design a system that allows users to store and access large files using cloud storage, metadata management,
and replication for reliability.
Q 94. Design a cache eviction policy (Least Recently Used - LRU)
Description: Implement a cache management strategy that evicts the least recently used data when the cache is full to
make space for new data.
Q 95. Design a system for storing and querying billions of rows of data
Q 90. Design a recommendation system like Amazon's product recommendations
Description: Build a system that suggests products to users based on their preferences and behavior, utilizing collaborative
filtering, content-based filtering, and hybrid methods.

18. I build scalable data pipelines by creating modular components, using managed services like AWS Glue or Apache Airflow
for scheduling, and ensuring each part can scale independently as data volumes increase.
I optimize SQL queries by using indexes, selecting only necessary columns, minimizing complex joins and subqueries, and
reviewing the query execution plan to identify bottlenecks.
I ensure data quality by validating data at each ETL stage, setting up data profiling checks, removing duplicates, and
configuring automated alerts to monitor ongoing data quality.
Unstructured data can be stored in a data lake like Amazon S3. I use tools like Spark or Hadoop for processing, and I often
convert the data into structured formats like Parquet or ORC to simplify querying.
For analytics, I use star or snowflake schemas. Fact tables store quantitative data, while dimension tables hold descriptive
data. Proper indexing and key constraints further optimize performance.
Data partitioning divides large datasets into smaller segments, often based on criteria like date. This approach improves
query performance by allowing only relevant partitions to be scanned.
I am experienced with big data tools like Hadoop and Spark for processing, Kafka for real-time streaming, and AWS tools
such as EMR, S3, and Redshift for storage and analytics.
Amazon Redshift is a cloud-based data warehouse that handles large datasets with parallel processing and columnar
storage, making it ideal for analytics. I typically use Redshift with AWS Glue for ETL and Amazon S3 for data storage.
I ensure data security through encryption, access control, and compliance with regulations like GDPR or HIPAA. In AWS, I
Normalization reduces data duplication by organizing it into related tables, which is ideal for transactional systems.
Denormalization combines tables to make queries faster, which is useful for analytics.
Q 107: How would you handle unstructured data?
Q 111: How do you build and scale data pipelines?
Q 112: Describe your experience with big data tools.
Q 113: How do you handle data security and compliance?
Q 108: What strategies do you use to ensure data quality?
Q 110: Describe schema design considerations for analytics.
Q 109: Can you explain data partitioning and why it’s important?
Q 106: How does Amazon Redshift work, and how do you use it?
Q 105: What is the difference between normalization and denormalization?

19. use IAM for permissions, KMS for encryption keys, and CloudTrail for auditing.
A data lake, such as Amazon S3, stores raw, unstructured, and structured data, while a data warehouse, like Amazon
Redshift, is structured and optimized for fast analytics.
Caching speeds up data access by storing frequently accessed data in memory. It is useful for high-demand data and helps
reduce database load and improve response times.
Here, we have mentioned some important points to remember while preparing for the Amazon Interview:
Know Amazon’s Leadership Principles: Prepare examples that show customer obsession, ownership, and problem-
solving.
Practice Coding Daily: Focus on data structures and algorithms on sites like LeetCode and HackerRank.
Use STAR for behavioral Answers: Structure responses into situations, tasks, actions, and results for clarity.
Show Problem-Solving Approach: Break down problems and explain your thinking.
Learn System Design Basics: Understand scalability, reliability, and large data handling.
Prepare for Leadership Questions: Have examples ready that demonstrate teamwork, ownership, and resilience.
Also Read: Most Commonly Asked HR Questions and Answers 
In conclusion, preparing for the Amazon interview process requires a solid understanding of core concepts and problem-
solving skills. By studying common Amazon interview questions and practicing Amazon interview questions with answers,
candidates can gain confidence and improve their chances of success. A focused approach to technical and behavioral
questions helps demonstrate Amazon's skills and values. Remember, thorough preparation is key to showcasing your
abilities effectively.
Q 114: What is the difference between a data lake and a data warehouse?
Q 115: How does caching improve data access, and where would you use it?
Simple Tips and Tricks for Cracking Amazon Interview 
Conclusion