Prefect won’t solve the memory usage of your file size or storage.
Regarding persisting results - it depends. If you require the actual output of the processing (e.g. there is artifact data required as input to the next), then you would need to persist those results yourself (writing to file, or however you might do that natively).
If the action is idempotent (say a file or action is taken to write some piece of data into a database) and you don’t need to repeat the action, only know that the action was already taken successfully, you can use results cacheing with minimal effort