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