Shopify + BigCommerce Senior Developer

Job Description

Do you have a desire to build enterprise commerce platforms that power some of the worlds most recognized brands Can you architect headless storefronts on Shopify Plus and BigCommerce Enterprise that are fast secure and built to scale Are you excited to use AI-assisted development tools to write better code faster without ever losing sight of engineering ownership and quality Do you thrive on solving complex B2B commerce challenges pricing quoting procurement and system integrations for global clients If you answered yes then we want to talk to you!

Were looking for a Senior Developer to design build and optimize enterprise-grade commerce experiences on Shopify Plus and BigCommerce Enterprise with a strong emphasis on headless and composable architecture. This role sits at the intersection of deep platform expertise and modern engineering practice youll work across the Shopify and BigCommerce ecosystems contribute to next-generation storefronts built on Hydrogen Catalyst and React and bring AI-assisted development into your daily workflow to accelerate delivery without compromising on architecture security or code quality.

Your platform depth consulting instincts and comfort operating at the leading edge of commerce engineering will ensure our clients get resilient high-performing solutions and a genuine technology partner. Youll collaborate closely with architects designers and client stakeholders throughout the project lifecycle and youll help shape the reusable accelerators prompts and best practices that raise the bar for the whole delivery team.

Responsibilities

Top 5 responsibilities:

1. Design develop and implement enterprise-grade eCommerce solutions on Shopify Plus and BigCommerce Enterprise including B2B commerce capabilities and third-party integrations.

1. Leverage AI-assisted development tools (Claude GitHub Copilot Codex Cursor or equivalent) for solution exploration code generation debugging unit testing documentation and code refactoring always reviewing and validating AI-generated output for security scalability and maintainability.

1. Architect and build headless and composable commerce storefronts using Shopify Hydrogen BigCommerce Catalyst and React applying server-side rendering (SSR) static site generation (SSG) and incremental static regeneration (ISR) as appropriate.

1. Contribute to reusable AI prompts engineering accelerators and coding best practices that improve delivery quality and consistency across the team.

1. Partner directly with clients to translate business requirements into scalable secure and performant technical solutions providing hands-on consulting and technical leadership throughout the engagement.

Additional Responsibilities:

• Build and extend Shopify Functions Checkout UI Extensions Customer Account Extensions Shopify Flow automations Metaobjects and Shopify Markets configurations.

• Develop against the Shopify Admin API Storefront API and GraphQL as well as BigCommerce Stencil Checkout SDK GraphQL Storefront API B2B Edition REST APIs and Webhooks.

• Implement enterprise B2B commerce features such as account hierarchies customer-specific pricing approval workflows quoting procurement and ERP/CRM/PIM integrations.

• Build modern engineering solutions using JavaScript/TypeScript React GraphQL REST APIs serverless functions edge functions and event-driven integrations.

• Optimize storefront performance against Core Web Vitals and Lighthouse benchmarks through CDN strategy caching image optimization lazy loading and performance profiling.

• Apply secure coding practices aligned to the OWASP Top 10 including OAuth JWT PCI awareness and secret management.

• Build and maintain CI/CD pipelines using GitHub Actions Azure DevOps Jenkins and Docker including Netlify/Vercel deployment workflows and release management.

• Uphold code quality through unit and integration testing static code analysis (SonarQube ESLint) code reviews root cause analysis and observability/monitoring practices.

• Collaborate with architects QA and client stakeholders across the full project lifecycle.

• Mentor junior developers and contribute to internal knowledge sharing and engineering best practices.

Qualifications

Top 5 qualifications:

1. 5 years of software development experience with mandatory production experience in both Shopify Plus and BigCommerce Enterprise.

1. Strong expertise in JavaScript/TypeScript React/ GraphQL REST APIs and Headless Commerce.

1. Proven experience implementing enterprise B2B commerce solutions including account hierarchies customer-specific pricing approval workflows quoting procurement and ERP/CRM/PIM integrations.

1. Hands-on experience leveraging AI-assisted development tools (Claude GitHub Copilot Codex Cursor or equivalent) to improve engineering productivity while maintaining high standards of architecture security and code quality.

1. Strong consulting debugging performance optimization communication and client-facing skills.

Additional Qualifications:

• Experience with Shopify Functions Checkout UI Extensions Customer Account Extensions Shopify Flow Metaobjects Shopify Markets Admin API Storefront API and GraphQL.

• Experience with BigCommerce Catalyst Stencil Checkout SDK GraphQL Storefront API B2B Edition REST APIs and Webhooks.

• Working knowledge of composable commerce architecture including Shopify Hydrogen and BigCommerce Catalyst and SSR/SSG/ISR rendering strategies.

• Familiarity with serverless and edge functions and event-driven integration patterns.

• Experience optimizing for Core Web Vitals and Lighthouse scores through CDN strategy caching image optimization lazy loading and performance profiling.

• Knowledge of secure API development OWASP Top 10 OAuth JWT PCI awareness and secret management.

• Hands-on experience with GitHub Actions Azure DevOps Jenkins Docker and Netlify/Vercel deployment pipelines.

• Experience with unit/integration testing static code analysis (SonarQube ESLint) code reviews and observability/monitoring tools.

• Experience with commercetools Adobe Commerce Salesforce Commerce Cloud Mirakl Marketplace or Marketplacer a plus.

• Familiarity with MCP (Model Context Protocol) and AI Agents a plus.

• Experience with Playwright Cypress or Storybook a plus.

• Understanding of accessibility standards (WCAG) a plus.

• Bachelors degree in Computer Science Engineering or a related field or equivalent practical experience.

What We Can Offer You

• A career with thought leaders who literally wrote the book on Marketplace Best Practices.

• A career in the fast-paced world of retail eCommerce digital marketplaces and platform businesses.

• A career with first movers who are deploying new business models and strategies worldwide.

• A career in a flat management structure without a rigid hierarchy and bureaucracy.

• A career in a culture that rewards creativity and innovation risk-taking and teamwork.

Additional Information

Our Core Values: Caring Adaptable Proactive Ownership Empowering Clients

Keywords: Shopify Plus Shopify Hydrogen BigCommerce Enterprise BigCommerce Catalyst Stencil Headless Commerce Composable Commerce React TypeScript GraphQL REST API B2B Commerce AI-Assisted Development GitHub Copilot Claude Cursor Codex SSR SSG ISR Core Web Vitals OWASP CI/CD SonarQube MCP commercetools

eCommerce & Marketplace Platforms: Shopify Plus BigCommerce commercetools Adobe Commerce (Magento) Salesforce Commerce Cloud (SFCC) Mirakl

Technology & Tools: CRM (Salesforce) PIM (Product Information Management) CPQ (Configure Price Quote) CMS (Content Management Systems) OMS (Order Management Systems) ERP (Enterprise Resource Planning) BI Tools (Business Intelligence)

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.