Sourabh Kaushik
Payments engineer. Builds and maintains ISO8583Studio, writes its guides, and runs the EMV certification and middleware engagements behind it at AiCortex Solutions.
Table of contents
About
Sourabh builds the tools he needed on payment integrations and did not have: a host that answers a 0200 the way a real acquirer does, a payShield that can be run on a laptop, a terminal that boots in an emulator, and calculators that show their work byte by byte. ISO8583Studio is that toolbox, released under the AGPL v3 so that other engineers can read exactly what it does.
The guides on this site come from the same work: the bitmap you misread, the PIN block format a switch expected, the TR-31 header a key-management team could not agree on. Each is written to be checked against a trace, not taken on trust.
Works on
Writing
The most recently revised guides. Each post shows its published and updated dates, and the four reference posts were re-checked against the standards in October 2026.