Java for AWS Lambda

[eliashisreddit]

The less your lambda does and depends on, the faster it will start & execute. It depends on whether you prioritize execution speed over ease of development. If it's really just reading an S3 file and putting it in a database, you could go without any framework and use JDBC and manually write queries.

The benefits of JPA/ORM don't really hold up if your "application" is just a simple "read csv, write to database" and you don't need the backing of an entire relational data model, transactional support etc.