Pulumi has introduced a streamlined process for protecting serverless application APIs using AWS's API Gateway and Lambda authorizers, making it easier for developers to implement OAuth authorization with Auth0. The process involves three main steps: defining a Lambda function and its authorizer using Pulumi’s AWSX package, writing custom authorization logic with Auth0 to handle access tokens, and integrating the Lambda authorizer with API Gateway to validate requests. Auth0 simplifies OAuth implementation by managing user authentication and authorization, while AWS Lambda authorizers provide custom logic for API access control. The AWSX package automates provisioning necessary resources, such as Lambdas and roles, though developers can override these as needed. The blog post offers examples of setting up API routes, custom authorization logic, and testing access with valid and invalid tokens, demonstrating the flexibility of AWS Lambda authorizers and encouraging developers to explore further with Pulumi’s resources and examples.