Data transformation
Yet another key use case for Lambda has been its ability to transform data on the fly. Say you have a stream of data coming into an S3 bucket in the form of one or more CSV files, each CSV file being different in size. For your application to process this data, it first needs to be transformed into a JSON file and then uploaded to a DynamoDB table. So, how do you get this done effectively? One way is to leverage an EC2 instance that will periodically poll or pull the CSV files from S3, transform it, and upload it to DynamoDB. However, this can have potential issues, for example: what happens when there are no files coming into S3 for a long time? Do you keep the EC2 instance up and running all this time? Also, polling or pulling the files from S3 will require its own set of logic that you will have to maintain, which can be an additional burden. So, what's the easy way out? You guessed it: Lambda functions!
For this particular use case, we will be creating a simple S3...
