Payments Platform Transformation Work

Guillermo's work

Selected transformations across payments delivery systems.

Grouped by theme. Each story reflects work Guillermo has done inside operating environments — reorganizing functions, modernizing systems, and building repeatable execution.

Payments and Platform Modernization

Helped build a full-stack payments platform with orchestration capabilities

Helped architect, lead, and build a full-stack payments platform for complex merchants and software partners that needed one integration layer for cards, ACH/eCheck, alternative payment methods, fraud screening, 3DS, tokenization, routing, webhooks, reporting, chargebacks, and settlement visibility. The platform connected global payment capabilities across many countries, currencies, gateways, and processors without forcing each merchant or partner to manage that complexity on their own.

Payment orchestration
global payments
platform strategy

Rebuilt a fragile settlement and reporting foundation

Led a tightly time-constrained effort to rebuild a settlement and reporting process that the business could no longer rely on. The work went back to the raw funding and settlement data, used processor-file integrity checks, and rebuilt the lifecycle around the actual source of truth. It replaced a large amount of inherited logic and manual repair work with a cleaner process that made reconciliation accurate, repeatable, and easier to operate.

Settlement
reporting
reconciliation
source of truth

Promoted AI-assisted engineering with real guardrails

Promoted the use of AI-assisted software engineering inside a payments data engineering environment, pairing modern coding agents, LLMs, and developer tools with clear rules, developer review, and normal pull request discipline. The work helped the data engineering team deliver a volume and complexity of work that would normally require a significantly larger team, while keeping production accountability in place.

AI delivery
data engineering
production discipline

Helped extend payment hardware into mobile commerce

Led the payment gateway work, wireless terminal applications, and Apple MFi certification behind a Bluetooth mobile receipt printer. The product became a major commercial success and helped the business move beyond traditional terminals into mobile payment use cases.

Mobile payments
Apple MFi
terminals

Operating Model and Enablement

Built the integration and developer experience function behind a complex payments platform

Created and led the integrations team and the developer experience work that helped merchants, software partners, and internal teams turn a complex payments platform into something customers could actually implement. The work replaced ad hoc technical support with a repeatable adoption model: integration documentation, test environments, sample code, certification, production onboarding, and go-live support. It became the bridge between platform capability and real customer usage.

API adoption
developer experience
partner enablement

Helped mature the operating functions a payments platform needed to scale

Helped create, formalize, or mature key functions around integrations, technology, product management, sales engineering, and data engineering as the platform and company grew. Some functions were new; others already existed but needed clearer ownership, better handoffs, and more consistent ways of working. That work helped the company move away from one-off requests and reactive direction toward a more scalable operating model.

Operating model
product discipline
sales engineering

Helped global partners turn payment hardware into complete solutions

Worked with payment hardware and software partners across the U.S., China, Latin America, India, Australia, the Middle East, and Asia-Pacific. The work connected partner requirements, payment flows, certifications, gateways, and customer use cases so the company could help partners deliver complete payment solutions.

Partner enablement
global delivery

Risk, Compliance, and Trust

Turned merchant underwriting into structured decisioning

Led the product and engineering work that turned merchant underwriting from a mostly manual review process into the first versions of a structured decisioning system. The work translated bank-specific underwriting rules, exceptions, and risk signals into clearer categories the business could review, explain, and improve. It changed underwriting from a queue of judgment calls into a foundation for faster, more consistent merchant onboarding.

Underwriting
risk
automation
auditability

Built the certification path for broader market access

Led software-side certification and compliance work across PCI DSS Level 1, PA-DSS, Mastercard TQM, and Apple MFi. That work helped turn technical compliance into market access by giving banks, gateways, software partners, and enterprise buyers a clearer basis for trust.

Certification
compliance
market access

Built gateway infrastructure that expanded a payment hardware business

Built and operated PCI DSS Level 1 gateway infrastructure for a payment terminal manufacturer. The gateway supported partners, deployed terminals, multiple processors, international card processing, and U.S. ACH, giving the company a software foundation for partner solutions instead of hardware sales alone.

PCI DSS
gateway
infrastructure

Early Foundations

Connected mobile field work to legacy operations

Built early mobile field systems for parking enforcement and retail restocking before mobile enterprise tools were mature. The work connected handheld ticketing, barcode scanning, wired and wireless synchronization, and undocumented legacy COBOL systems so field activity could flow back into core operations.

Mobile field
integration
legacy systems

Built early multi-rail infrastructure for real-world bill payment

Built and operated early gateway and kiosk infrastructure for a startup handling practical payment use cases: card, ACH, check, prepaid, cash acceptor payments, NACHA settlement, and Sprint PCS bill collection. The work tied payment rails, physical kiosks, settlement files, and customer-facing workflows into one operating system.

Gateway
kiosks
multi-rail

Started by turning business workflows into working systems

Built an ERP platform in Argentina and adapted it across municipal government, pharmacies, grain receivers, and seed producers. The work covered accounting, tax collection, GIS-supported municipal workflows, inventory, networking, servers, training, and day-to-day adoption — early practice in turning messy operations into systems people could use.

ERP
municipal
foundations