So far we have seen that certain applications can be broken down into one or more simple nuggets of code called as functions and uploaded to AWS Lambda for execution. Lambda then takes care of provisioning the necessary resources to run your function along with other management activities such as auto-scaling of your functions, their availability, and so on. So what exactly are we supposed to do in all this? A developer basically has three tasks to perform when it comes to working with Lambda--writing the code, packaging it for deployment, and finally monitoring its execution and fine-tuning.

In this section, we are going to explore the different components that actually make up a Lambda function by understanding what AWS calls as a programming model or a programming pattern. Currently, AWS officially supports Node.js, Java, Python, and C# as the programming languages for writing Lambda functions, with each language following a generic programming pattern that comprises of the following concepts.