The Learn assignment tool allows students to upload (multiple) files for assessment. The marker can then access these files and provide grade(s) and/or feedback via the same interface.
There is no file upload size limit, however, if you are expecting students to upload large files, please advise them to leave plenty of time for the upload to complete. If possible, you should advise them to upload from the University network.
Rubrics can be attached to assignments, to help students better understand how marks will be assigned. Rubrics also facilitate giving standardised feedback for large cohorts.