Senior Ruby on Rails Developer – Freelance

We’re looking for a pragmatic, experienced Senior Ruby on Rails Developer to take ownership of key backend systems across our platform. In this freelance role, you’ll play a pivotal part in ensuring the performance, scalability, and reliability of our e-commerce infrastructure. From designing robust APIs to refining data models and optimizing performance at scale, you’ll be central to the continued growth and stability of our tech stack.

Join us and help shape the backend foundation of a fast-moving, product-focused e-commerce business.

Contract: Freelance (6 months, renewable)
Location: Remote (with CET timezone overlap)
Start: ASAP
Contact: Armand Fardeau, Head of IT

Mission Focus

We're looking for a Senior Ruby on Rails Developer to join our core backend team as an independent contractor. This mission is central to our platform’s performance, scalability, and reliability. You’ll contribute to key backend initiatives focused on:

• API development for internal and external clients

• Data modeling and business logic in support of our e-commerce and operational features

• Performance optimization, ensuring robust response times and system throughput at scale

You’ll be embedded in a backend team of 5 and collaborate closely with our frontend engineers and product managers.

Key Deliverables

• API Services: Design, build, and maintain scalable RESTful APIs

• Domain Modeling: Extend and optimize business logic using ActiveRecord and PostgreSQL

• Performance Tuning: Optimize queries, background jobs (Sidekiq), and caching strategies (Redis)

• Code Quality & Testing: Ensure high-quality, maintainable code with RSpec, RuboCop, and SimpleCov

• Security by Design: Apply secure coding practices and data protection principles

Success Metrics & Reporting

• Performance: Fast, reliable APIs (response times, throughput)

• Velocity: Timely delivery of scoped tasks with minimal bugs

• Stability: Low downtime, high availability, and resilient code
  Team Feedback: Strong collaboration and communication across product and frontend teams

Weekly check-ins and async updates are expected.

Collaboration & Tools

• Team: Backend team (5 developers), Frontend team, Product managers

• Stack: Ruby on Rails, PostgreSQL, Sidekiq, Redis, REST APIs, ActiveRecord

• Tooling: Bitbucket, CircleCI, Heroku, Docker

• Testing & Quality: RSpec, RuboCop, SimpleCov

• Workflow: Jira, Slack, Figma

Contract & Payment

• Invoicing: Monthly

• Legal: NDA required

• Timezone: Must maintain at least 5 hours overlap between 08:00–18:00 CET

• Remote: Fully remote, European time zone preferred but not mandatory

Next Steps

If you’re interested, please share:

• Your availability (start date)

• Your hourly or daily rate (in EUR)

• A few relevant project examples or references

• Your GitHub or portfolio