Which language is Amazon written in?

Amazon uses multiple programming languages depending on the specific task, team, or service. While there is no single language that powers all of Amazon, here are the primary languages used across the company:

1. Java

Java is one of the most widely used languages at Amazon, particularly for backend services and large-scale distributed systems. Its reliability, scalability, and performance make it ideal for Amazon’s vast infrastructure. Many of Amazon’s core services, especially those related to e-commerce and AWS, are built using Java.

2. C++

Amazon uses C++ for systems that require high performance and low-level operations. It’s commonly used in areas where speed and efficiency are critical, such as high-performance computing and hardware-level applications.

3. Python

Python is used extensively in various areas, including:

• Automation and scripting
• Data analysis and machine learning with tools like AWS SageMaker.
• Cloud applications with AWS Lambda and Boto3, the AWS SDK for Python.

4. JavaScript/TypeScript (Node.js)

For frontend development and some backend services, Amazon uses JavaScript and TypeScript, especially for web applications. Node.js is frequently used in building scalable APIs and microservices.

5. Ruby

Ruby is used in some of Amazon’s web development efforts, especially in the past when Ruby on Rails was popular for quickly building web applications. Although it's less dominant now, it’s still used in some parts of the company.

6. Go (Golang)

Go is gaining popularity at Amazon for developing microservices and highly concurrent systems, thanks to its efficiency and simplicity for building distributed systems.

Summary of Programming Languages Used at Amazon:

• Java: Dominates backend and large-scale services.
• C++: Used for high-performance and hardware-related tasks.
• Python: Popular for automation, data science, machine learning, and AWS applications.
• JavaScript/TypeScript (Node.js): Used for frontend development and APIs.
• Ruby: Present in some web applications.
• Go: Used for modern microservices and distributed systems.

How to Prepare for Amazon's Coding Interviews

To increase your chances of success in an Amazon coding interview, focus on mastering coding patterns and data structures commonly tested in their interviews. Check out Grokking the Coding Interview: Patterns for Coding Questions, which is designed to help you learn the most frequently tested coding patterns in interviews.

Additionally, for system design roles, Grokking the System Design Interview can help you develop a solid understanding of scalable system architecture, which is a key aspect of senior technical roles at Amazon.

By mastering these programming languages and patterns, you’ll be well-prepared for Amazon’s technical interview process.