Posts are stored in the blockchain and not censurable to some extent. Fetching of the blockchain data is done through polling of public apis (blockfrost or koios). Posting a message requires a Cardano transaction which implies fees but this would also prevent spam.

Private messages between users are encrypted with a public key generated from each user wallet signature.

The whole app is hosted on github pages and open source: https://github.com/alucao/decon

Any feedback or thoughts are welcomed.