React jobs in Brazil

Senior Full-Stack Engineer (Ruby on Rails + React) Remote | Full-Time (40+ hrs / week) | Fast-Growth Startup | Contract or Contract-to-Hire

We are a fast-growing, VC-backed retail audit & execution platform that helps brands diagnose planogram compliance and optimize merchandising and category management workflows. Our tools connect real-world retail execution with an intelligent analytics backend powered by data, video workflows, and CVAI.

We're a small, highly collaborative, and fast-moving team. You'll work directly with founders, technical leadership, and product teams — influencing architecture decisions, shaping internal tools, and contributing to high-impact product areas.

• Core Product Development:
  • Build and maintain data-driven dashboards using Ruby on Rails + React
  • Develop backend logic, algorithms, and data pipelines in Rails
  • Improve and expand internal Admin tooling for operations, analytics, and sales
  • Work on backend components powering the mobile app used by field shoppers Ensure consistency between mobile data flows and dashboard experiences.
• Collaboration & Code Quality:
  • Work closely with the CTO to ensure backend data is translated into clean, functional UX
  • Communicate timelines, tradeoffs, and constraints to non-technical founders
  • Provide thoughtful code reviews for junior developers Mentor junior developers on architecture and best practices (not people management)
• Platform & Infrastructure:
  • Build and integrate APIs between internal systems and external services
  • Work with third-party tools (marketing automation, payments, workflow systems)
  • Improve performance, maintainability, and reliability across the codebase
  • Identify and fix bugs across frontend, backend, web, and mobile
  • Write unit tests and elevate testing best practices over time
  • Maintain clean, well-structured, well-documented code

• Must Have 5–8+ years of full-stack engineering experience
• Strong proficiency with Ruby on Rails (backend, APIs, logic, data flows)
• Strong proficiency with React (frontend features, UI state, components)
• Experience working across the stack : backend services, APIs, frontend, and internal tools
• Ability to work with both new systems and existing / legacy code
• Experience with data handling, scaling, and performance optimization
• Startup mindset: adaptable, fast, independent, detail-oriented Strong communication skills, especially with non-technical stakeholders
• Experience reviewing code and mentoring junior developers
• Bonus Skills React Native AWS Background jobs (Sidekiq, queues, workers) Data modeling or data pipeline experience

Who Thrives Here You're a builder at heart.

You enjoy owning full features end-to-end — backend logic, data models, UI, APIs, integrations, dashboards, internal tools.

You like fast-moving environments where engineering decisions directly impact the roadmap. You're comfortable collaborating with both technical and non-technical founders.

If you want the chance to build core product DNA in an early-stage company, this role is for you.

A supportive and collaborative team environment.

• Opportunities to work on diverse and challenging projects;
• Flexible working conditions;
• 12 vacation days per year;
• 5 sick days per year;
• English classes.
• Access to psychologist support for mental well-being.