Full-Stack JavaScript Engineer (Remote - LATAM or Europe)

Senior Full-Stack JavaScript Engineer

About

At POS+ (posplus.org), we build the foundational payment interface software that powers modern retail, B2B, and service-industry transactions. Our payments architecture requires flawless data consistency, zero-downtime availability, low latency, and bulletproof offline-first capabilities. We build mission-critical infrastructure that businesses rely on to process their livelihoods. Because our platform manages complex real-time event loops, financial calculations, and deep peripheral integrations, the quality of our codebase is our highest priority. We are looking for a true Senior Engineer—someone who architectures scalable systems, actively maps out edge cases, and writes highly maintainable code. We have zero tolerance for AI slop, unreviewed copy-pasted code, or hidden technical debt. We expect our senior engineers to have deep foundational knowledge, a critical eye for code quality, and the ability to explain the why behind every line of code they push.

Responsibilities

• Architect, build, and maintain highly scalable full-stack features using Node.js, React, and TypeScript.
• Optimize complex database queries and schema designs (SQL/NoSQL) to handle massive transaction volumes.
• Secure and scale our RESTful and WebSocket APIs to ensure instantaneous synchronization between physical POS software and our cloud infrastructure.
• Proactively identify and eliminate technical debt, enforcing strict linting, type safety, and comprehensive testing frameworks.
• Work as a direct independent contractor, collaborating synchronously with our core product and engineering leadership.

Requirements

• 5+ years of verified professional experience running production-grade full-stack JavaScript/TypeScript applications.
• Production experience dealing with asynchronous programming challenges, race conditions, memory management, and event-driven architectures in Node.js.
• Deep knowledge of React state management, rendering optimization, and building accessible, modular UI components.
• Strong communication skills in English—comfortable thinking out loud, defending architectural choices, and collaborating live via video calls.
• Experience with cloud infrastructure (AWS/GCP), CI/CD pipelines, and Dockerized environments is a major plus.
• This is a fully remote role, targeting LATAM or Europe time zones for team overlap.