SIGNiX is a pki-based digital signature platform.  SIGNiX's FlexAPI is used to private label digital signatures for leading platforms like zipLogix (80% of USA's 1.15 million real estate agents), Pershing (NetX360 is the platform for >40% of US brokerage accounts).  In addition to managing the digital signature workflows via web services, we are the source of the completed documents, data, signature and audit trail.  We move that content (push or pull API) to the "trusted" central system.  SIGNiX is extending that model to make the same entry the immutable ledger, with the same key pair used to create the transaction for the central system.  We need full stack Ethereum smart contract developer.