I minimise costs by using a mix of GAE and AWS: Host the main application on GAE but for background services use AWS. E.g I use AWS SES for mails and S3 for sto

I minimise costs by using a mix of GAE and AWS: Host the main application on GAE but for background services use AWS. E.g I use AWS SES for mails and S3 for storing uploads and blobs. Also storing objects that don't need indexes as pickled blobs in a parent model helps a lot. The advantage over JSON is that you don't need extra code to parse, (de)serialized and validate the object.