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Portrait photo of Roniel Lopez
Software Project Leader at Mercado Libre

Building resilient systems
that scale.

12+ years of experience crafting high-availability software, leading teams, and shipping products across fintech, e-commerce, and travel tech.

About

A bit about me

I'm a Software Project Leader at Mercado Libre, where my team builds fraud scoring systems that evaluate over 1 billion transactions per day across Latin America. Before Mercado Libre, I led 15+ engineers at Sabre building high-throughput microservices with 99.7% uptime, and worked on payment systems at Verifone. My journey started in Cuba, where I earned a CS degree from UCI with a thesis on AI-driven decision-making and published research on open-source desktop environments. Since moving to Uruguay in 2021, I've built products across fintech, travel tech, and marketplace fraud prevention at continental scale.

Location
Montevideo, Uruguay
Company
Mercado Libre
Role
Software Project Leader
Focus
Fraud Prevention at Scale
Education
CS Engineer — Universidad de las Ciencias Informáticas (UCI), Cuba (4.96 GPA)
Languages
Spanish (Native), English (Advanced)
Self-Hosting Automation Games Music Travel Hiking Books Cars
Experience

Work Experience

Nov 2024 — Present

Software Project Leader

Mercado Libre · Montevideo, Uruguay

  • Lead and mentor a team of 7 backend engineers building real-time fraud scoring systems that evaluate over 1 billion transactions per day across 8 Latin American markets.
  • Drive fraud prevention strategy contributing to nearly $1B USD in approval improvements while maintaining chargeback rates below 0.20% in major markets.
  • Architect the technical roadmap for anti-fraud systems, aligning engineering priorities with business risk objectives across multiple countries.
  • Partner with Data Science and Analytics teams to build proactive, data-driven fraud detection models that achieve 96–99% approval rates across the region.
Java Go Python Spring Boot Agile Data Analytics
Oct 2021 — Nov 2024

Lead Software Engineer

Sabre · Montevideo, Uruguay

  • Developed microservices in Java, including a reverse proxy with load balancing, throttling, and circuit breakers (Spring Boot/Webflux).
  • Designed and implemented performance test cases to ensure system reliability.
  • Built an admin web app for the reverse proxy (Angular).
  • Automated CI/CD with Jenkins and Ansible; deployed to GCP with metrics, dashboards, and Redis.
  • Managed a team of 15+ developers.
Java Go Webflux Angular GCP Jenkins Redis
Jan 2021 — Sep 2021

Senior Software Engineer

Switch Software Solutions (Verifone) · Montevideo, Uruguay

  • Developed microservices for payment gateway-to-terminal communication (Spring Boot).
  • Maintained and extended a monolith application built with Spring.
  • Designed performance test cases for system reliability.
  • Migrated a web app from AngularJS to Angular 2.
Java Spring Boot Angular Performance Testing

Plus 8+ years of prior experience in fintech and software engineering.

Want the full details?

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Skills

Skills & Technologies

Backend

Core systems and APIs

Java Go Python Spring Boot WebFlux Node.js Hibernate R2DBC

Frontend

Web and mobile interfaces

React Angular TypeScript HTML/CSS Swift

Databases

Storage and caching

PostgreSQL MySQL MongoDB Redis

Cloud & DevOps

Infrastructure and delivery

GCP AWS Docker Kubernetes Terraform Jenkins Ansible CI/CD

Architecture

Patterns and principles

Microservices RESTful APIs Reactive Programming Design Patterns Clean Code SOLID TDD

Leadership

Teams and processes

Team Leadership (15+ engineers) Agile / Scrum Technical Roadmaps Code Reviews Mentoring Performance Testing
Contact

Let's work together

Have a project in mind or want to discuss an opportunity? I'd love to hear from you.