Founding Full-Stack Engineer

This isn't just another senior role. This is an invitation to join the founding team of a well-funded startup on the brink of global expansion.At Expanly, we're solving a multi-billion dollar problem: advertising platforms that waste millions of dollars because they ignore the business fundamentals that actually matter. We're building the control center that puts smart retailers back in the driver's seat.Fresh off a major funding round, we are looking for foundational engineers to architect the core of our platform as we launch across Europe and beyond. If you're driven by impact, ownership, and the chance to build a category-defining product from the ground up, we want to talk to you.The RoleAs a foundational Senior Full-Stack Engineer, you'll be a key architect of the Expanly platform. This is a role of immense impact where you'll build the core features our customers use every day. Reporting directly to the CTO, you'll have significant ownership over our product's codebase, from the back-end logic that crunches complex data to the intuitive front-end our users love. Your mission: design, build, and scale our application using Node.js and React. With our recent funding accelerating our launch into new markets, you will be building the core features that deliver our value proposition to a growing international user base. You'll translate complex business logic and vast data sets into a powerful, performant, and intuitive user interface. You'll build robust APIs, manage data flows, and ensure our application is scalable and reliable. You won't just be closing tickets—you'll be making key architectural decisions that directly influence our product's usability, performance, and ability to scale.This is a rare opportunity to join a company at a pivotal moment. You won't be inheriting legacy systems or significant technical debt. You'll be creating the ideal product from an early stage and shaping the engineering culture for years to come.You will report directly to our co-founder and CTO, Samuel Backman. Samuel has been building software since 2012, progressing from developer to technology director at companies like Qvik and Mavericks Software. He provides the deep technical expertise key to building a scalable and robust product, and is focused on creating an engineering culture of ownership, excellence, and pragmatism.What We're Looking ForWe value deep technical expertise, a proactive mindset, and a genuine passion for building elegant, user-centric products.Technical Excellence:Back-End Mastery (Node.js): Deep, hands-on expertise in Node.js and TypeScript. Proven experience building scalable, secure, and performant REST or GraphQL APIs.Front-End Proficiency (React): Strong command of React and its modern ecosystem (e.g., Hooks, Context). You can build complex, data-rich user interfaces from the ground up.Database Experience: Solid experience with relational (e.g., PostgreSQL) and/or NoSQL (e.g., MongoDB) databases. You understand how to model data and write efficient queries.Testing & Quality Focus: Strong commitment to writing clean, maintainable, and well-tested code. Experience with testing frameworks like Jest, React Testing Library, or Cypress is essential.Cloud & DevOps Familiarity: Comfortable deploying and managing applications in a cloud environment (GCP is a plus). Experience with Docker and CI/CD pipelines (e.g., GitHub Actions) is highly valued.Architectural Mindset: You understand software architecture patterns and can make pragmatic decisions that balance speed with long-term quality.Essential Qualities:Exceptional written and spoken English communication skillsEntrepreneurial mindset with the ability to thrive in a fast-paced startup environmentStrong problem-solving skills and the ability to work autonomously, taking ownership of your domainExperience working effectively with remote, distributed teamsGenuine passion for building products that solve real business problems for usersNice to Have:Previous experience in e-commerce, advertising technology (AdTech), or retailDirect experience in an early-stage startup environment, understanding the need for speed and adaptabilityWhat We OfferCompelling Compensation Package with Life-Changing Equity:Competitive Base Salary: €48,000 - €66,000 per year, based on your experience and impact. Your specific salary within this range will be determined by your level of experience and alignment with our internal compensation framework, ensuring fairness across the team.Foundational Team Equity: As a core member of our founding team, you won't just get options; you'll get a meaningful stake in the company. Our goal is to build a company with a valuation exceeding 100M€ in the next four years. For a foundational team member, an equity stake of this size could be worth well over 1,000,000€. This is your opportunity to own a piece of the engine you help build and share directly in our monumental success.Professional Growth & Impact:Front-row seat to the future of e-commerce technologyDirect collaboration with globally respected brands and household-name webshopsOpportunity to champion award-winning, proven technologyVisible impact on product direction and company strategyA World-Class Environment:Our Helsinki Innovation Hub: We operate on a strategic hybrid model designed for deep innovation and global reach. Our Product and Engineering teams are centered at our Helsinki headquarters to foster the high-bandwidth, in-person collaboration crucial for solving complex problems and driving our core product forward. This role is based in our Helsinki office. Culture of Ownership & Trust: Real autonomy without corporate red tape. We prioritize results over hours logged.Tools for Success: Your choice of a new MacBook or PC, a home office stipend, and a modern SaaS toolstack.Connection & Wellbeing: Comprehensive health coverage, regular virtual get-togethers, and annual all-expenses-paid company retreats to connect as a team.About ExpanlyFounded in Helsinki, Finland, by a team with deep experience from companies like Swappie, Verkkokauppa.com, and Foodora, Expanly is on a mission to fix a fundamental flaw in e-commerce. Retailers pour millions into platforms like Google and Meta, letting algorithms advertise without understanding margins, inventory, or strategy. We give that control back. Our platform connects real-time business data directly to ad campaigns, resulting in smarter, more profitable advertising.The market is responding. We are already trusted by major retailers like Tokmanni, Reima, and Varusteleka. Our technology was recently named "Innovation of the Year" at the 2025 eCom Summit & Awards.Now, with the backing of top investors from success stories like Wolt and Swappie, we have secured the funding to scale globally. You are joining at a pivotal moment: we have product-market fit, an award-winning solution, and the capital to build a world-class company.Expanly is an equal opportunity employer committed to diversity and inclusion. We welcome applications from all qualified candidates regardless of race, gender, age, religion, sexual orientation, or disability status.