Senior RoR & React Developer

This role is ideal for a Senior Fullstack Developer with strong experience in Ruby on Rails and modern frontend frameworks like React, along with skills in automated testing, CI/CD, and complex application development. Best suited for those comfortable working remotely within EMEA time zones, especially if they enjoy startup dynamics and product innovation. Familiarity with AWS and a proactive, collaborative mindset are strong pluses.

1. How do you structure a scalable SaaS app using Ruby on Rails and React?
   Use Rails as an API backend with serializers (e.g., ActiveModel::Serializers), modular services for business logic, and React with a component-based architecture and routing for the frontend.

2. What’s your approach to debugging complex Rails applications in production?
   Use logs, error trackers like Sentry, byebug for local debugging, performance profiling tools, and write isolated tests to identify root causes.

3. Describe how you manage state in a React application that integrates with a Rails backend.
   Use React Context or Redux for global state, local component state where appropriate, and sync with backend via RESTful APIs or GraphQL with Axios or Fetch.

4. What experience do you have with CI/CD pipelines using GitLab or similar tools?
   Set up GitLab pipelines for linting, testing, and deployment, integrate with AWS or Heroku for staging/production, and use environment configs for secrets and deployment variables.

5. How do you ensure multilingual support and localization in a Rails and React stack?
   Use I18n in Rails for backend responses, react-i18next for frontend translation, and manage translation files centrally with JSON/YAML; ensure dynamic language switching.

6. What’s your process for test automation in fullstack applications?
   Use RSpec and Capybara for Rails tests, Jest and React Testing Library for frontend, and run all in CI with code coverage reports and automatic regression checks.

7. How do you handle performance optimization in database-heavy Rails applications?
   Apply indexing, eager loading with includes, raw SQL for complex queries, query batching, and monitor with tools like New Relic or Bullet.

8. Describe a challenge you solved with AWS in a recent project.
   [Example] Used AWS S3 for asset storage, CloudFront for CDN, Lambda for scheduled tasks, or RDS for scalable database hosting; managed permissions via IAM roles.

9. How do you ensure seamless collaboration on a remote team across time zones?
   Document processes clearly, maintain async communication via Slack/Docs, overlap for standups or critical reviews, and use tools like Loom or GitHub for detailed feedback.

10. What methods do you use to keep user experience consistent while localizing apps?
    Ensure layout adapts to text expansion, RTL support, dynamic placeholders, locale-specific formatting (dates, currencies), and regular QA in multiple languages.

OnTheGoSystems is hiring a Senior RoR & React Developer to help build a new multilingual SaaS platform using Ruby on Rails, React, and AWS. This 100% remote role supports European, Middle East, or African time zones and offers high-impact, product-focused work on a global solution. You'll contribute across the stack, from database design to CI/CD, in a collaborative startup environment. Benefits include a remote-friendly culture, personal development budgets, physical activity support, and global holiday observance—ideal for developers ready to shape a product used by millions.