Under the Stack: Episode 3 - Testing payments where it actually breaks

In‑person payments don’t fail in a boardroom. They fail at the checkout, when the queue is building, the customer is waiting, and the pressure is very real. And yet, one of the most critical parts of the payment stack, testing, is often overlooked or treated as an afterthought.

In this episode of Under the Stack, David Frank, Head of Sales at PaytestLab joins Victor Padee, CRO at Aevi, to unpack the hidden complexity of payment testing. From fragmented hardware setups and multiple integration types to the growing number of payment methods and regional variations, they explore why testing is far more than just “running a transaction”, and why getting it wrong has real business consequences.

Drawing on real retailer scenarios and hands‑on experience, they break down what effective testing actually looks like in modern in‑person environments. From the limitations of manual testing and the risks of relying on simulators, to the role of automation in scaling quality and speeding up release cycles, this conversation gets into the realities teams face behind the scenes. They also explore the true cost of downtime, the operational drag of outdated testing processes, and why automation is quickly becoming a baseline, not a bonus.

This episode breaks down:

• Why payment testing is far more complex than it looks
• The difference between standalone, semi‑integrated, and fully integrated environments
• Why manual testing doesn’t scale (and where it still matters)
• The risks of relying on simulators instead of real‑world environments
• How automation enables faster, safer release cycles
• The hidden cost of downtime, and what poor testing really impacts
• How to define your testing scope before investing in tools or frameworks

If you are navigating in‑person payments, managing payment infrastructure, or trying to deliver reliable checkout experiences at scale, this episode is a must‑listen.