About the role

Role Overview

Senior Full-Stack JavaScript Engineer (Fully Remote, targeting LATAM or Europe time zones). You will architect and maintain scalable full-stack features for mission-critical payment infrastructure.

Responsibilities

Architect, build, and maintain highly scalable full-stack features using Node.js, React, and TypeScript.
Optimize complex database queries and schema design for massive transaction volumes (PostgreSQL/MongoDB).
Secure and scale RESTful and WebSocket APIs for near-instant synchronization between POS software (cloud and server) and POS+ cloud infrastructure.
Proactively identify and eliminate technical debt, enforcing strict linting, type safety, and comprehensive testing.
Collaborate as a direct independent contractor with product and engineering leadership.

Requirements

5+ years of verified professional experience running production-grade full-stack JavaScript/TypeScript applications.
Strong asynchronous programming skills in Node.js, including race conditions, memory management, and event-driven architecture.
Deep React knowledge (state management, rendering optimization, accessible modular UI components).
Strong English communication; comfortable explaining architectural decisions and collaborating live.

Nice to Have

Experience with AWS/GCP, CI/CD pipelines, and Docker.

Screening / Interview Process

Intro & System Design (45 mins) with a live system architecture exercise.
Live Code Review & Debugging (60 mins) where you review and refactor a messy codebase, identifying issues (security, architecture, concurrency) and improving maintainability.

About POS+

POS+ builds payment interface software for modern retail, B2B, and service-industry transactions. The platform focuses on mission-critical payments infrastructure requiring strong data consistency, zero-downtime availability, low latency, and offline-first capabilities.

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

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