SeniorFull TimeEN
We Elevate. Digitally.
SQLI is a European player and market leader in customer experience and digital transformation, helping major international brands create value through technology and digital innovation. From strategy to the effective implementationof technological solutions, we design and build robust, high-performance architectures and engaging digital experiences, combining advanced technologies, proven methodologies, and deep expertise.
To strengthen our teams (2,200 employees across 12 countries), we are looking for driven talent who share our values: Creativity, Engagement, and a Future-minded approach.
From our Diegem office, you will operate at the heart of the business, partnering with experienced sales colleagues and key stakeholders across delivery, finance, and operations to shape and close high-impact opportunities.
We’re looking for a Shopify Back-end Developer who takes ownership of the technical backbone of our e-commerce projects.
You don’t just write code, you build robust, scalable solutions that make a real impact. From custom integrations and app development to optimizing performance and architecture, you ensure every Shopify build is ready to perform, scale, and evolve.
We are looking for a Senior Shopify Backend Developer to support the delivery of mid to large-scale ecommerce projects, often in headless architectures and involving multiple integrations (ERP, PIM, middleware).
You will play a key role in designing and implementing backend services and Shopify apps, working closely with architects, Product Owners, Business Analysts and frontend teams.
Job Description
You handle complex problems without overcomplicating things.
You break them down and keep moving forward.
You take ownership of what you build.
From idea to release, you make sure features actually work in practice.
You work well within existing systems.
Architecture, integrations and middleware don’t slow you down, you know how to improve them.
You keep things practical.
No unnecessary complexity, just solid solutions that get the job done.
Shopify Backend Development
Develop and maintain custom apps on Shopify
Work extensively with:
Admin API (GraphQL)
Webhooks (event-driven flows)
Metafields & custom data structures
Implement backend logic using Shopify Functions and Checkout extensibility
Integration & Data Flows
Design and implement integrations with:
ERP systems (SAP, Odoo, MS Dynamics, …)
PIM systems
POS (kassa systems)
Backend Engineering
Build scalable backend services using:
TypeScript / JavaScript
Node.js
Work with frameworks such as NestJS or similar structured backend frameworks
Must-have
5+ years in backend development
Proven experience with Shopify APIs & app development
Experience in:
Remix, Polaris, Liquid, Storefront API, Admin API, GraphQL, Shopify APP extensions, Shopify APP, Typescript, Shopify Flow basics, Shopify configuration
Experience with event-driven architectures (webhooks, async processing)
Nice-to-have
Experience with NestJS, React Router 7, PHP, Tailwind CSS basics, Hydrogren theming
Experience in headless commerce architectures
Exposure to B2B ecommerce (pricing, catalogs, workflows)
Strong problem solver in complex environments
Able to design and deliver features end-to-end
Comfortable working with existing architecture & middleware
Pragmatic mindset (not over-engineering)
Highly competitive salary package
Hospitalization insurance
Company car with charging card
Meal allowance & monthly allowance
Phone subscription and laptop
Flexible cafeteria plan
13th month salary and holiday allowance
Access to multiple offices across Belgium
Hybrid working model with 2 to 3 days remote, depending on client meetings and pitches
International collaboration across 12 countries, working with diverse teams and markets
A high-performance environment where initiative and ownership are expected and recognized
Direct exposure to senior stakeholders and decision-makers, both internally and on the client side "