Lambda

Receives two json encoded objects on invoke:

Context
Methods and Attributes
Event
One or more records

Limitations

512MB /tmp ephemeral disk
1024 threads max
300 second execution time

Redshift Database Loader (pre-loaded function) example will push data from s3 on trigger, ETL and load to redshift

Blogs

https://aws.amazon.com/blogs/compute/amazon-kinesis-firehose-data-transformation-with-aws-lambda/

https://aws.amazon.com/blogs/compute/implementing-a-serverless-aws-iot-backend-with-aws-lambda-and-amazon-dynamodb/

https://aws.amazon.com/blogs/database/indexing-metadata-in-amazon-elasticsearch-service-using-aws-lambda-and-python/

Docs

https://docs.aws.amazon.com/lambda/latest/dg/with-ddb.html

Code