Back End Developer

About Belong

Belong is pioneering FanTech by building the financial infrastructure of fandom. Our platform bridges the gap between cultural engagement and secure financial systems, turning fan activity into verified identity, exclusive access, and real economic value. We are backed by a premier group of investors, including a16z speedrun, Lakestar, Backward Capital, and Prevail, as well as an outstanding circle of angel operators and entrepreneurs.

By connecting fan behavior with production-ready banking infrastructure, we enable fans to be recognized for their loyalty while allowing artists to participate in the financial value their communities generate.

Our team is led by Nick Holmsten, Founder of Tunigo (acquired by Spotify) and former Global Head of Music at Spotify, and Ash Pournouri, former manager of Avicii and serial entrepreneur behind several community-led initiatives, including Triller, Nordic Angels and Super Human Network. At Belong, we aren't just building a rewards app, we are building the technical rails that make belonging economically meaningful.

About the Role

We are looking for a Backend Developer to join our core engineering team in Sweden. You will be a key member of a team dedicated to building the financial infrastructure for fandom, creating financial and user engaging systems that connect artists with fans. You will work in a modular, AI-driven environment where security, compliance, quality, speed, and ownership are the guiding principles.

Requirements

• 3+ years of backend development with Node.js/TypeScript.
• Experience with relational databases (e.g., PostgreSQL), ORMs, and cloud infrastructure.
• Strong knowledge of API design, authentication (JWT/OAuth), and testing frameworks.
• Familiarity with containerization and orchestration (Docker/Kubernetes) and serverless patterns.
• High ownership in a fast-paced startup, with a focus on secure, performant code.
• Commitment to the "Definition of Done": code that is thoroughly tested (Unit, Integration, E2E) and monitored in production.
• Experience working in a strictly regulated environment (fintech, payments, or banking, or similar).
• Work and collaborate with international partners on integrations and feature development.
• Innovate and develop tools and processes to enhance team productivity.
• Swedish work permit.

Responsibilities

• Research, Plan and Develop and services using TypeScript/Node.js Build and scale high-concurrency social and financial features to support real-time user engagement.
• Maintain and expand critical financial integrations, ensuring absolute ledger integrity and secure transaction management.
• Execute technical roadmaps for social data integrations to fuel fan-scoring and identity features.
• Use AI code agents and multiple LLMs to 10x your performance while maintaining full responsibility for security and performance.
• Adhere to strict security and compliance standards and best practises.

Nice-to-Haves

• Experience with AWS infrastructure, K8s, IaC andCI/CD.
• Experience on automated monitoring and structured logging practices.
• Working experience within high performant/scalable systems
• Contributions to the Open Source Community.
• Experience on core banking, transaction management, reconciliation methods, KYC/AML and similar.

What We Offer

• Work location: Stockholm.
• Competitive Compensation: Market salary + competitive equity package.
• Impactful Work: A rare chance to redefine fandom and fintech for the US market
• Dream Team: Join a passionate, top-tier, music-loving team building something extraordinary.
• Key Role: Your work will directly shape the financial infrastructure that connects artists with their fans.