Cases

Cases from the field

Situations we struggled with during EMV projects: integrating tools, getting test cases to pass and solving implementation challenges. Each case explains what happened, why, and how it was fixed, so you can save time on yours.

2026-11-13 · Tool integration

Integrating Mastercard's Test Environment Interface (TEI)

What changes when Mastercard's TEI drives your contactless Level 2 system: the shift from manual testing, the architecture, the TEI Server messages and the test sequence.

What the cases cover

Tool integration

Connecting test tools, simulators and test automation to a terminal or kernel.

Test cases

Level 2 and Level 3 test cases that failed, and why.

Implementation challenges

Design and integration problems met while building EMV acceptance.

How cases are written

Most cases follow this outline, adapted to the subject.

  1. Context. The project, kernel, terminal and tools involved.
  2. Symptom. What went wrong and how it showed up: a failed test, a decline, a crash.
  3. Investigation. How we narrowed it down: logs, traces, tags, test tool output.
  4. Root cause. What was actually wrong.
  5. Fix. What we changed, and how we verified it.
  6. Lessons. What to check first next time.

Have a case to share?

Tell us about a problem you solved, or one you are stuck on, through Support.