We tried Keeping the Daap as much as decentralized as possible. We made sure to not have any sort of extra storage rather than blockchain itself, We made sure the transaction between the accounts to be peer to peer, that is our Dapp should not receive any sort of funds that were used for bidding purposes by other users, as it may lead to gas expense issue for the users who did not win the auction. We had meta transaction in our mind, Only the winning bid must be transacted but due to time constraints we were not able to do that, but we came up with the solution created a function that can only be used/triggered by the address of the winning bid on the product auction. Our ledger maintains all bidding info.
For some reason, the matic testnet was not responding at 10:38 Nov 22 just during the hackathon submission, our contract transaction hash:- 0x6cab17f4e413b87723aada52203c4554780657e8a71f0d7dad827c0bf0c1324c There testnet were down so we had to make submission video on kovan.