AWS Lambda, a service for developing serverless applications, allows developers to execute functions triggered by various events without managing servers. Middleware, a design pattern that turns common tasks into reusable components, can be used to streamline Lambda functions, and Middy.js is a popular middleware engine specifically designed for Node.js AWS Lambda functions. Middy.js simplifies code management by providing a robust ecosystem of inbuilt middleware for tasks like input validation and error handling, enhancing modularity and maintainability. This tutorial guides readers through using Middy.js to create a simple blog app, demonstrating how to set up a project, write custom middleware, utilize inbuilt Middy middleware, test Lambda functions locally, and deploy applications. The use of Middy.js in AWS Lambda projects can lead to cleaner and more manageable code, supported by a vibrant community for continuous development and support.