Guillermo's career began building business systems from the ground up: ERP software in Argentina, municipal workflows, accounting systems, tax collection, inventory, networking, servers, training, and user adoption.

He then moved into early mobile field systems: parking enforcement, retail restocking, handheld devices, barcode scanning, wired and wireless synchronization, and integration into undocumented legacy COBOL systems.

From there he moved deeper into payments: early wireless PalmOS payment applications, direct connectivity to First Data, payment kiosks, cash acceptors, ACH/NACHA files, and multi-rail gateway operations.

At an Asia-founded global payment terminal and mobile payments company with operations across China, the U.S., and Latin America, he worked across payment hardware, gateway infrastructure, PCI DSS Level 1, PA-DSS, Mastercard TQM, Apple MFi, wireless terminals, and payment solution delivery. Much of that work involved partners, banks, gateways, software providers, and enterprise customers who needed practical answers for how payment solutions would actually be built, certified, deployed, and supported.

At a full-service payments provider, he helped modernize settlement and reporting, expand payments orchestration, automate merchant underwriting, improve developer integration enablement, build operating functions, modernize cloud infrastructure, and advance data engineering and AI-assisted delivery. He also worked closely with partners, platforms, and customer-facing teams to turn complex payment capabilities into solutions customers could understand, implement, and operate.

Through Gleaning Capital LLC, he personally funds live-environment development of automated, data-driven systems — a proving ground for disciplined automation, AI-assisted development, and production discipline under real consequences.

Today he brings that executive operating experience into focused outcome-based engagements for companies whose payment delivery systems have outgrown their current operating model.