Full-stack Developer at Mercive

Are you the kind of person who sees a problem and takes ownership of it end-to-end? Do you thrive when you get to shape how a project comes together, not just execute on a spec, and do you treat AI as a serious multiplier for what you can build? Then you might be the person we're looking for at our office in the center of Copenhagen.

Mercive is a fast-growing Shopify e-commerce agency based in Copenhagen. We're the right match if you want to join a team that pushes boundaries and solves real business problems through design, technology, and strategy. We believe AI is fundamentally changing how software gets built, and we're putting it at the core of how we work, not as a gimmick, but as a genuine multiplier for quality, speed, and what's even possible to deliver. We're looking for builders with an entrepreneurial mindset: people who take initiative, own outcomes, and hold themselves accountable without waiting to be told.

The Role

You'll work on e-commerce projects where AI is increasingly part of how we build, whether that's AI-assisted coding to move faster, building AI-powered features into client projects, or automating away repetitive work. We don't expect you to be an AI expert on day one, but we do want someone genuinely curious and eager to push what's possible. The developers who thrive here are the ones who experiment, find leverage, and bring new approaches to the team.

Shopify is our main focus. The tech stack varies by project: native Shopify work in Liquid, HTML, and CSS, and headless builds in Remix.js / Next.js (still very much relevant). You'll be a key part of larger projects, from platform migrations to Shopify, to building new storefronts and custom solutions, where you help define the technical requirements and figure out the best way to get things over the finish line. That means understanding the client's business needs, weighing trade-offs, and making informed architectural decisions alongside the team.

As a full-stack developer, you'll also build and maintain backend services and APIs, primarily using Node.js on Google Cloud, and develop Shopify apps that require both frontend and backend work.

This is a fast-paced environment where the opportunities for growth are endless, and where the people who take ownership and run with things go furthest.

Responsibilities

• Take ownership of technical direction within larger projects, including platform migrations to Shopify, defining requirements and driving implementation decisions with minimal hand-holding

• Explore, adopt, and champion AI-assisted development tools and practices to improve delivery speed, code quality, and what we're able to build for clients

• Build AI-powered features into client projects and find new ways to automate repetitive work

• Develop projects, features, backend services, and improvements in a performant and well-tested way

• Build and maintain APIs and backend services using Node.js

• Develop Shopify apps that span both frontend and backend functionality

• Work closely with the project management team and other stakeholders (Backend, UX, etc.) to scope, plan, and deliver new projects and features

• Craft code that meets our internal standards for style, maintainability, security, and best practices in a high-scale web environment

• Consistently ship features and improvements with minimal guidance

• Advocate for improvements to quality, performance, and scalability that have broad impact across the team

• Solve technical problems of high scope and complexity across both frontend and backend

• Provide mentorship for Junior and Intermediate developers to help them grow and remove blockers

Qualifications

• An entrepreneurial mindset: a self-starter who takes initiative, owns outcomes, and holds themselves accountable

• Familiarity with AI-assisted development tools (e.g. Cursor, Claude Code, GitHub Copilot), or a strong drive to master them

• Experience with e-commerce and Shopify (including Shopify apps) is a strong plus

• Professional experience with Next.js, Remix.js, or another modern JavaScript framework (Vue, Angular, Ember, etc.)

• Professional experience with Node.js and building APIs or backend services

• Experience working with cloud platforms, preferably Google Cloud

• At least 3 years of professional working experience

• Experience using Git in a professional/workplace environment

• A solid understanding of semantic HTML, CSS, and core JavaScript concepts

• Experience with performance, scalability, and optimization problems, and a demonstrated ability to diagnose and prevent them

• Positive, solution-oriented mindset, with strong organizational skills

Benefits

• Daily lunch at Restaurant Lalala

• Coffee, soda & snacks in the office

• Friday bars & fun events

• Office located in central Copenhagen

If you can see yourself being a part of Mercive, please send us your CV and a description of why you are interested in this role.

You need to be located close to Copenhagen to be considered for this job.

We're looking for someone to start on 3 August 2026, so you should be available to begin then (or shortly after).