In the early days of software development, anyone seeking to develop a web, mobile, or backend application had to own the hardware required to run a server, which is an expensive process. Then, when cloud computing came, it became possible to lease server space or a number of servers remotely. As a result of this, serverless computing allows developers to purchase backend services on a pay-per-use basis, which means that only what they use must be paid for. Serverless computing refers to the ability to run code without maintaining your own servers. The term "serverless" doesn't refer to the absence of servers, but rather to the fact that the servers, operating systems, network layer, and rest of the infrastructure have already been configured so you can focus on writing the application code. AWS Lambda is a compute service that lets you run code without provisioning or managing servers. You don't have to worry about any infrastructure with AWS Lambda since it's a fully managed service. For instance, you can develop backends using AWS Lambda and Amazon API Gateway to authenticate and process API requests. The Lambda functions can perform a variety of tasks, from serving web pages to processing streams of data to calling APIs and integrating with other AWS services such as CloudWatch, API Gateway, S3, SNS, and more. When a function is created, Lambda packages it into a new container and then executes that container on a multi-tenant cluster of machines managed by AWS. Before the functions start running, each function's container is allocated its necessary RAM and CPU capacity. Once the functions finish running, the RAM allocated at the beginning is multiplied by the amount of time the function spent running. The customers then get charged based on the allocated memory and the amount of run time the function took to complete. AWS Lambda supports a number of the most popular languages and runtimes such as Nodejs, Python, Ruby, Java, Go, and C#. With AWS Free Tier, you can run 1 million requests for free. Also if you'd like to estimate your AWS Lambda architecture cost you can use the AWS Pricing Calculator. To get started with AWS Lambda, you can create, invoke, and manage the Lambda functions using any of the following interfaces: AWS Management Console, AWS Command Line Interface (AWS CLI), AWS SDKs, or AWS CloudFormation. In this tutorial, I will use the AWS Management Console to create our Lambda function using NodeJS. To implement a NodeJS function to trigger a new build endpoint from the Bitrise API, you need to install different node modules and then create a new file with the name index.js at the root of the project. You can test the function by running the following command: node index.js And if it is successful run, you will find the output like the following: Congratulations, you did it! You created your first serverless function using AWS Lambda to trigger a new Bitrise build using Bitrise API.