Serverless Lambda functions can change the way we think about development by allowing us to start projects as simple static front-ends and use serverless functions to glue together different microservices. To build a Slack messenger service, we used Netlify Functions with Netlify's Identity feature to access and update user data. We also restricted access to the serverless Lambda function using JavaScript in the handler method and updated the app_metadata of a user to enforce only one message per hour. Additionally, we triggered a serverless function every time a new user signed up by connecting it to a Netlify event hook. With these capabilities, developers can build powerful real-world applications while still benefiting from the scalability and cost-effectiveness of serverless computing.