Senior Back-end Engineer (PHP/ Ruby on Rails)

They are a high-growth fintech startup transforming how e-commerce brands protect and recover their revenue. Their platform automates chargeback prevention and dispute response, turning what has traditionally been a manual and frustrating process into a fast, intelligent, and efficient workflow.

Job Summary

We’re looking for a Senior Back-end Engineer who thrives in fast-paced environments and excels at evolving complex, business-critical systems. In this role, you’ll own a key area of our payments dispute resolution platform and lead the strategic effort to migrate it into a stable, scalable, and reliable product.

This is not a project for incremental refactoring or simple technical debt cleanup. You will actively investigate our legacy system, reconstruct functional requirements, and execute an incremental platform migration to a modern architecture.

Responsabilities

• Drive the incremental migration strategy from the legacy system to the replacement implementation, managing user/data migration and rollout/rollback planning.

• Investigate the existing PHP system to document functional requirements, validate feature parity, and ensure zero regressions during the transition.

• Take full ownership of a core business domain, building foundational cross-system testing, monitoring, and documentation.

• Write, review, and architect code while systematically migrating features without slowing down product delivery.

• Collaborate closely with offshore development team to manage handoffs and maintain alignment.

• Make high-judgment technical choices that balance immediate migration needs with long-term architectural maintainability.

Qualifications and Requirements

• 5+ years of professional software engineering experience.

• Strong PHP experience, with meaningful Ruby exposure.

• Proven experience analyzing, modifying, and safely migrating large, complex production systems with limited test coverage and incomplete documentation. (Direct "legacy" experience is a strong plus, but equivalent complex system migration experience is accepted).

• Proven track record of ownership, requirements reconstruction, and delivering complex migration projects end-to-end.

• High comfort level working independently and making critical technical decisions with imperfect information.

• Based in LATAM with full-time availability to overlap with US or Canada time zones (Fully Remote).

What We Offer

• 100% Remote Work: Enjoy the freedom to work from the location that helps you thrive. All it takes is a laptop and a reliable internet connection.

• Highly Competitive USD Pay: Earn an excellent, market-leading compensation in USD, that goes beyond typical market offerings.

• Paid Time Off: We value your well-being. Our paid time off policies ensure you have the chance to unwind and recharge when needed.

• Work with Autonomy: Enjoy the freedom to manage your time as long as the work gets done. Focus on results, not the clock.

• Work with Top American Companies: Grow your expertise working on innovative, high-impact projects with Industry-Leading U.S. Companies