Full Stack Developer - Ruby on Rails and React

Overview

Matrix One is a leading provider of software solutions for life science companies, helping them build, launch, and support better and safer products. Our mission is to streamline the product development and compliance process, enabling companies to bring medical devices to market faster and more efficiently.

Role description

We're looking for a Full Stack Developer to join the team behind Matrix eIFU, a monolithic SaaS application built on Ruby on Rails and React. Our customers are medical device manufacturers, and the software they rely on must meet the highest standards of reliability, traceability, and correctness. We are ISO 9001 certified, which means quality isn't an afterthought — it's embedded in how we design, build, test, and document everything we ship.

You'll work across the entire stack — from database models and background jobs to polished React components — and play a key role in shipping features, maintaining compliance, and expanding the platform's capabilities.

We are actively bringing AI into both the product and the way we work. That means building AI-powered features for our customers, and using AI tooling to move faster, write better code, and ship with more confidence. We're looking for someone who is genuinely excited about both sides of that.

This is a hands-on engineering role for someone who is comfortable navigating a mature codebase, taking ownership of end-to-end features, and holding themselves to a high standard of quality and documentation.

Stack overview

Backend

• Ruby on Rails as the core framework
• PostgreSQL for persistent storage
• Redis for caching and session management
• Sidekiq for background job processing
• Devise + Auth0 (OmniAuth) for authentication, CanCanCan for authorization
• CarrierWave + AWS S3 for file storage and uploads
• ActionCable for real-time WebSocket features
• Mailgun for transactional email, Sentry for error tracking

Frontend

• React with Redux and React Router
• Webpacker / Babel build pipeline
• i18next and react-i18next for internationalization

Infrastructure & Tooling

• Heroku for deployment, Docker + docker-compose for local development
• GitHub for source control
• CircleCI for continuous integration and automated test runs
• RSpec, Capybara, Cucumber, Jest, and React Testing Library for testing
• RuboCop and ESLint/Prettier for code quality

Responsibilities

• Design, build, and maintain features across the Rails backend and React frontend
• Write clean, well-tested code using RSpec (unit/integration) and Jest (frontend)
• Contribute to and improve the existing Cucumber/Capybara end-to-end test suite
• Work with PostgreSQL to design schemas, write efficient queries, and manage migrations
• Build and maintain Sidekiq background jobs for async processing workflows
• Collaborate on API design between Rails controllers/services and React components
• Participate in code reviews on GitHub and help uphold engineering standards via RuboCop and ESLint
• Keep CI green — investigate and fix failing CircleCI builds promptly
• Debug and resolve production issues using Sentry and application logs
• Help improve CI/CD pipelines and deployment processes
• Produce clear technical documentation for features, changes, and processes in line with our ISO 9001 quality management system
• Follow and contribute to established quality procedures, including change control, traceability, and audit readiness
• Contribute to the integration of AI-powered features into the product, working with LLM APIs and related tooling
• Help shape how the team adopts AI in its day-to-day development workflow — from code generation and review to testing and documentation

Strong fit

• 3+ years of professional experience with Ruby on Rails
• 3+ years of professional experience with React (ideally with Redux)
• Solid understanding of PostgreSQL — schema design, migrations, query optimization
• Experience with background job processing (Sidekiq or similar)
• Comfort working in a monolithic Rails + Webpacker application structure
• Familiarity with Redis for caching and session storage
• Experience writing tests with RSpec, Capybara, and/or Jest
• Working knowledge of AWS S3 or equivalent cloud storage services
• Experience with Docker for local development environments
• Proficiency with Git and GitHub — pull requests, code review, branch workflows
• Familiarity with CircleCI or a comparable CI platform

Nice to have

• Hands-on experience integrating LLM APIs (OpenAI, Anthropic, etc.) into production applications
• Familiarity with AI-assisted development tools (e.g. GitHub Copilot, Cursor, Claude) and a habit of using them effectively
• Experience with Auth0 or similar identity providers / OAuth flows
• Familiarity with ActionCable / WebSockets in Rails
• Experience building internationalized (i18n) applications (multi-language, multi-locale)
• Familiarity with Heroku platform deployments
• Exposure to Cucumber / BDD testing workflows
• Experience with Mixpanel or other product analytics tools
• Prior experience working in an ISO 9001 or similarly certified environment
• Familiarity with regulated industries such as medical devices, life sciences, or aerospace — particularly around traceability, audit trails, and change control

What we offer

• Opportunity to work on a SaaS platform that directly supports the medical device industry
• A quality-first engineering culture backed by ISO 9001 certification
• A codebase with strong tooling, code quality standards, and CI in place
• Autonomy to take ownership of features from design to deployment
• A team actively embracing AI — both in the product and in how we build it
• A collaborative team that cares about shipping reliable, well-documented software
• 100% remote with full flexibility.
• Competitive benefits package.
• Annual company meet-ups in different international locations.
• Clear growth path to become a senior member of the team.