jagannath desai
payments infrastructure consultant, bangalore. twenty years in cards and payments - started in terminal firmware and pos applications, moved through acquirer switches and issuance processors to wallets, gateways and softpos.
build payment systems, take them through certification - various card schemes, nexo, pci (dss, ssf, mpoc) - and stay past go-live: support, maintenance, upgrades. customers across multiple regions. domains covered along the way: credit/debit, prepaid, transit, loyalty, dcc, petro.
hsm and key management is home ground - rki, pki.
these days building backend services for payments, and newer ground: device attestation and root of trust.
some public code:
fmcrypto - crypto and pki service. key generation, wrapping, dukpt, pin translation, certificates. public subset of a larger device management platform.
sarvantaryami - enterprise ai that runs fully offline against local llms. sql, rag and api agents.
nfc-link-writer - small react native app for writing urls to nfc tags.
most of the work is in private repos, client and product code.