Senior Full-Stack Developer

Company Description

McFadyen Digital is the leading advisor and implementer of eCommerce Marketplace solutions. During 15 years of implementing marketplaces weve built dozens of platforms that cumulatively generate billions of dollars of gross merchandise value (GMV). Were honored to have supported 10% of the Fortune 500 with their digital marketplace initiatives. Over 250 global brands like ABB AB InBev ACCO Albertsons American Red Cross American Eagle Outfitters US Army US Agriculture Dept (and many more) have entrusted their digital transformations to McFadyen. We operate global offices across the US Brazil and India. McFadyen Digital has been a trusted employer for over 39 years and believes that people are the most important part of our company. Were proud of our Great Place to Work certification.

Learn more about us at our website:

The Opportunity

Were looking for a Senior Full-Stack Developer with a strong backend focus to join a fast-moving marketplace project on a short-term contract basis. Youll design and build composable commerce services on commercetools and stand up seller and catalog flows through Mirakls dropship model integrating the two into a seamless buyer and seller experience. This is a hands-on delivery role for an engineer who can own backend architecture ship production-grade APIs and integrations quickly and contribute to the frontend where needed. If you thrive in headless API-first environments and want high-impact work with clear deliverables over a defined engagement this role is for you.

Engagement Details

• Engagement type: Independent contractor (project-based).
• Duration: 34 month project engagement with potential to extend based on project needs.
• Availability: Full-time (40 hours/week) for the duration of the engagement.
• Location / work model: Fully remote. Open to candidates based in the US Latin America (LATAM) or Canada with meaningful overlap with US business hours.
• Start: September/2026

Responsibilities

Top 5 Responsibilities

1. Design build and maintain scalable backend services and APIs on commercetools to power catalog cart checkout and order flows in a headless composable architecture.
2. Implement and configure Mirakl dropship capabilities seller onboarding offer and catalog ingestion order routing and shipment/tracking workflows and integrate them with commercetools and downstream systems.
3. Develop robust secure integrations between commercetools Mirakl and third-party systems (OMS ERP PIM payment and shipping providers) using REST GraphQL webhooks and event-driven patterns.
4. Deliver production-ready code on an aggressive project timeline including automated tests error handling logging and documentation suitable for handoff at the end of the engagement.
5. Collaborate with architects product and frontend engineers to translate requirements into technical solutions and contribute frontend work (React/Node) where the project requires it.

Additional Responsibilities

• Build and maintain commercetools extensions subscriptions and API clients; manage project settings types and custom fields.
• Configure Mirakl connector flows and reconcile marketplace data (offers orders messaging and payouts) with the commerce platform.
• Optimize performance reliability and scalability of backend services and integration points.
• Participate in code reviews technical design discussions and daily agile ceremonies (standups sprint planning retrospectives).
• Troubleshoot and resolve production and integration issues quickly during the engagement.
• Document architecture integration specs and runbooks to ensure a clean transition to the client/internal team at project close.

Qualifications

Top 5 Qualifications

1. 6 years of professional software engineering experience with a primary focus on backend development ( and/or Java) in production eCommerce environments.
2. Hands-on demonstrable experience building on commercetools (APIs projects extensions subscriptions and composable/headless commerce patterns).
3. Practical experience implementing Mirakl specifically the dropship model including seller/catalog/offer ingestion and order and shipment workflows.
4. Strong integration expertise: REST and GraphQL APIs webhooks event-driven architecture and connecting commerce platforms to OMS/ERP/PIM and payment/shipping providers.
5. Full-stack capability with enough frontend proficiency (React TypeScript JavaScript) to contribute to UI work when needed.

Additional Qualifications

• Bachelors degree in Computer Science or a related field or equivalent practical experience.
• Experience with cloud platforms (AWS Azure or GCP) and CI/CD pipelines (Docker Kubernetes or similar).
• Familiarity with marketplace business models seller operations and dropship fulfillment.
• Solid grasp of API security authentication/authorization and data privacy best practices.
• Experience delivering under contract or consulting engagements with tight well-defined timelines.
• commercetools and/or Mirakl certification is a plus.
• Comfortable working independently in a remote distributed agile team.
• Excellent written and verbal English communication skills.

Additional Information

Our Core Values: Caring Adaptable Proactive Empowering Clients

Keywords: Full-Stack Developer Backend Developer commercetools Mirakl dropship marketplace composable commerce headless commerce Java React TypeScript API integration GraphQL eCommerce contractor remote job

Equal Opportunity Employer

McFadyens goal is to ensure that our clients are able to maximize the return on their technology investment by providing better service to their clients partners and internal teams. At McFadyen we truly believe our employees are our most valuable asset. Across our locations in the US Brazil and India we offer a world class work culture that enables top notch delivery for some of the worlds most influential companies.

McFadyen Digital is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race color age religion sex sexual orientation gender identity / expression national origin disability protected veteran status or any other characteristic protected under federal state or local law where applicable.