Fullstack developer Shopify

Your mission
Your mission is to master the Shopify Plus ecosystem to build the world's most advanced platform for on-demand manufacturing. You will push the boundaries of Shopify, developing custom applications and sophisticated theme architecture to translate the Zellerfeld vision of sustainable, custom-fit footwear into a seamless digital experience. Your work will transform our Shopify store from a simple sales channel into the central operating system for our unique products.

Key Responsibilities

• Custom Shopify App Development: Architect, build, and maintain mission-critical custom Shopify Apps that power our unique on-demand manufacturing model, customer foot-scanning process, and circular recycling program.
• Advanced Theme Architecture: Lead the development of a highly customized and performant Shopify theme, using Liquid, JSON templates, and modern JavaScript to create an immersive digital showroom that effectively communicates our technology and brand story.
• API & Systems Integration: Design and implement robust, scalable integrations between Shopify Plus and our core manufacturing systems, ERP, and third-party logistics partners using Shopify's GraphQL and REST APIs.
• Platform Architecture & Strategy: Act as the primary technical authority on the Shopify platform, defining the overall architecture and data structures (Metafields, Metaobjects) to support our complex product and fulfillment logic.
• Future Headless Strategy & Prototyping: Develop the long-term technical roadmap for our e-commerce platform, including researching, prototyping, and evaluating a future transition to a headless architecture to unlock next-level performance and user experiences.
• Backend Logic & Automation: Leverage modern Shopify features, including Shopify Functions and Flow, to customize backend business logic (e.g., checkout, shipping, promotions) and automate key operational workflows between sales and production.
• Performance & Optimization: Continuously monitor and optimize the entire Shopify environment for speed, Core Web Vitals, and conversion, ensuring a best-in-class customer experience from landing page to checkout.
• Collaboration & Mentorship: Collaborate closely with product, design, and manufacturing teams to translate complex requirements into elegant technical solutions. Mentor junior developers and establish best practices for high-quality Shopify development.

Your profile
Required

• Shopify App Development: Proven ability to build, deploy, and maintain custom Shopify Apps from scratch using and React. Experience with Shopify's CLI, authentication (OAuth), and webhook systems is essential.
• Advanced Shopify Theme Development: Deep expertise in building complex, high-performance themes using Liquid, Sections, Blocks, and modern JSON templates. Must be proficient in integrating modern JavaScript (ES6+) for dynamic and interactive user experiences within the theme.
• Shopify APIs: Expert-level proficiency with Shopify's APIs. This includes deep, hands-on experience with both the Storefront API (GraphQL) for fetching data on the frontend and the Admin API (REST & GraphQL) for backend integrations and custom app logic.
• Modern Frontend Frameworks: Strong proficiency in React. This is the foundational skill for advanced theme components, custom apps, and any future headless development.
• Core Web Technologies: A rock-solid foundation in JavaScript (ES6+) and TypeScript, along with expert-level HTML5 and CSS3/Sass.

Nice to have:

• Headless Commerce Frameworks: Experience with modern headless frameworks like or Remix. Familiarity with Shopify's own stack (Hydrogen and Oxygen) is a significant plus.
• Advanced Data Modeling: Practical experience using and structuring data within Shopify's modern data platform, including extensive use of Metafields and Metaobjects to build complex product and content models.
• Modern Shopify Backend Tools: Experience leveraging Shopify Functions to write custom backend logic and Shopify Flow to create complex automation workflows.
• DevOps & CI/CD: Proficiency with version control (Git) and experience setting up and managing CI/CD pipelines for automated testing and deployment.
• Performance Optimization Tools: Hands-on experience using tools like Google Lighthouse, WebPageTest, and browser profiling tools to diagnose and improve Core Web Vitals and overall site performance.
• Architectural & Strategic Thinking: The ability to think beyond a single task to design and architect scalable, long-term solutions. Must be able to evaluate the trade-offs between different technical approaches (e.g., theme vs. app vs. headless).
• Problem-Solving & Ownership: A proactive and solutions-oriented mindset. The ability to independently identify technical and business problems, and take full ownership of projects from conception to completion.
• Communication & Collaboration: Excellent communication skills, with the ability to clearly articulate complex technical concepts to non-technical stakeholders (e.g., designers, marketers, product managers).
• Mentorship: A willingness to guide and mentor other developers, helping to establish best practices and elevate the technical skill level of the entire team.

Why us?
Join Us
We are an early-stage startup redefining how shoes are made—powered by 3D printing and a bold vision. In this role, you won't just be supporting innovation; you'll be leading it in one of the most critical areas of our production system

Team and Work-Life
At our Hamburg HQ, you'll join a diverse, multidisciplinary team of engineers, creators, and entrepreneurs. Our flat hierarchy and collaborative culture ensure your expertise and ideas are always heard. We believe in challenging the norm—and having fun while doing it.

Diversity
We value diverse perspectives and unconventional paths. What matters most is your passion, your know-how, and your ability to deliver impact.

About Us
Zellerfeld is revolutionizing the footwear industry with the world's first 3D-printing technology for fully customizable shoes. Our goal is simple: printed shoes on every foot. We're a passionate team of engineers, designers, and innovators, questioning the status quo and disrupting traditional manufacturing processes. Backed by founders, influencers, and celebrities who believe in our vision, we're committed to making a lasting, positive impact—not just on the footwear industry, but on the world.