Enabling Issuer Host Debugging for a specialized payments infrastructure provider in the U.S.

How Lithos helped a U.S.-bound payments infrastructure provider avoid certification bottlenecks and accelerate issuer host deployment.

A leading card-processing infrastructure provider expanding from LATAM into the U.S. needed to certify its issuer host across Visa, Mastercard, and Discover DCI, without wasting scarce network certification windows. Payhuddle’s Lithos compressed a multi-month debugging and readiness process into weeks, enabling first-attempt certification success.

Background

Founded in 2020, this company is one of the leading infrastructure providers in LATAM, serving over 50 partner banks and operating across multiple brands. Now expanding into the U.S. market, they are building innovative banking and payment solutions, including a multi-brand, multi-tenant issuer host designed to power the next generation of community banking in the country.

The challenge

They had built issuer hosts before. They knew the process. But the U.S. market was new territory, and they were not willing to proceed with formal certification with Visa, Mastercard, and Discover DCI without first pre-validating their issuer host.

Despite strong in-house debugging and certification expertise, the team ran into challenges that internal capability alone could not easily solve:

1. Certification windows with networks are scarce and hard to reschedule. Walking in underprepared means missed slots and extended timelines. In the U.S. market, those windows are particularly difficult to obtain.

2. Their test environments were layered and complex, with multiple networks, multiple message formats, and a large volume of test case scenarios to cover simultaneously.

They needed more than just a tool. They needed a structured, reliable way to pre-validate their issuer host so that, when they formally engaged the networks, they were ready.

Why did they choose Lithos?

They evaluated multiple tools. What made Lithos the right choice was not any single feature, but that it solved the entire problem in a single, centralized place.

Before Lithos, debugging and certification readiness were treated as two separate exercises, each requiring its own environment, process, and overhead. Lithos brought both together on a single platform: the team could debug their issuer host and run certification readiness tests in the same place, against the same scenarios, without switching tools or rebuilding test environments.

Other decisive factors included:

• Support for both ISO 8583:1987 and ISO 8583:1993 message formats, covering compatibility across all target networks.
• Up-to-date test plans for Visa, Mastercard, and Discover DCI issuer host certification.
• On-screen issue identification: Lithos pinpoints exactly where a problem is occurring and guides the user toward resolution, right in the interface.
• Payhuddle’s support team responded in hours, not days, a meaningful advantage for a team working against tight certification timelines.

How Lithos helped: From evaluation to certification confidence

Lithos allowed the customer to self-debug and validate their issuer host in-house without waiting for formal network debugging windows. The real-time analyzer and test case traceability provided the accuracy and confidence they needed before entering formal certification.

The results across three key areas:

1. From months of iterative debugging to certification-ready in weeks

Certifying an issuer host across three networks manually typically involves months of iterative cycles, failed attempts, and rescheduled network windows. By pre-validating in-house with Lithos, the team compressed what is typically a multi-month effort into a structured process measured in weeks.

2. First-attempt certification success

Every failed certification attempt carries a real cost: waiting weeks for the next available network window, increased project expenditure, and delayed go-live. Lithos ensured the team had identified and resolved issues before formally engaging with the network, enabling them to achieve their Letter of Authorization (LoA) on the first attempt across all three networks.

3. One platform for debugging and certification readiness

Debugging and certification readiness used to mean two separate environments, doubling the overhead. Lithos unified the entire workflow: debugging, running test cases, analyzing results, and tracking progress against Visa, Mastercard, and Discover DCI certification requirements, all in a single place. This also gave the team significantly better visibility across the process, reducing manual tracking overhead.

The outcome

With Lithos, the team pre-validated their issuer host across Visa, Mastercard, and Discover DCI before opening formal certification projects with the networks. Debugging cycles became faster and more structured. Test cases were centralized and mapped directly to certification requirements.

When they entered formal certification, they were ready. Their team achieved Letters of Authorization across all three major U.S. payment networks on the first attempt, avoiding rescheduled windows and extra costs and getting their transactions live faster.