If you ask this question a dozen different times you will probably get a dozen different answers (And probably 11 of them would work!) - But, if it were me, I would do something like this: Judging Form - Airtable Universe
This gets a little tricky as the individual datapoints needed from each judge starts to grow pretty quickly - Essentially you are needing 70 individual pieces of data from each of of your 15 judges. That can be a lot to collect through a form or interface!
I would have the judges submit an individual form for grading of every project - So instead of asking them to fill out 70 fields, they would be filling out 7 fields, 10 times (If that makes sense). The form is in the “Voting Submissions” table, and the data collected from this is summarized in a formula. I just did straight average of all their ratings, but the different metrics could be weighted however you wanted.
Again, there’s probably a simpler or better way to do this (And the users on this forum will no doubt come to the rescue), but hopefully a few of these concepts help.