Reusable and efficient code often requires passing dynamic values at runtime. These runtime values may be environment types, file paths, path to store logs, table names, and more. With the help of environment variables, Lambda functions allow us to pass dynamic values at runtime. As a result, the code becomes reusable without making any changes to it.
Environment variables are key-value pairs and these key-value pairs are encrypted/decrypted using the AWS Key Management System (KMS). Key-value pairs can be defined at the time of creating a Lambda function. Externally configured environment variables are also accessible within the Lambda function, using standard APIs supported by the different programming languages. For example, Node.js functions can access environment variables using process.env, where process.env refers to an object in Node.js. In Node...