Full-time, Senior, Location: remotely, ±2 hours from EU timezone

We are looking for a Senior Full-stack Engineer to architect, engineer, and optimize the core infrastructure of our funnel-driven, multi-vertical platform. In this role, you will ensure a robust, secure, and scalable foundation for future growth by developing and integrating advanced MarTech solutions, payment processing systems, and continuously evolving our backend.

Fjor is a consumer health company dedicated to developing an AI-powered nutrition assistant that empowers individuals to maintain and enhance their overall health and well-being while making personal self-care accessible, efficient, and enjoyable. The flagship project of Fjor is the Keto Diet App, an industry-leading iOS application catering to the keto and low-carb market in the USA, which has achieved over $20M in sales, 5M installations, and 500K subscribers since launch.

We are a highly effective, small team of 16 people, with experience from top tech companies such as Uber, Google, Booking.com, Flo, Scentbird, Yandex, Tinkoff, and Alfabank. Our fully remote team operates with a main hub in Amsterdam. We value flexibility, independence, and aim to keep bureaucracy to a minimum. Learn more about our founders, Evgeny Severenkov & Andrew Kopanev.

• Keto Diet App: https://apps.apple.com/us/app/keto-diet-app-carb-tracker/id1406879426
• Keto Diet App site: https://www.myketo.care/
• Formula iOS App: https://apps.apple.com/us/app/formula-weight-loss-diet-app/id6511248415
• Formula Care: https://www.formula.care/
• Fjor Linkedin Page: https://www.linkedin.com/company/fjor-wellness/

1. Develop and Maintain Scalable Systems: Architect secure, scalable backend services using modern frameworks, managing complex codebases for robust performance and scalability.
2. Execute Key Deliverables: Deliver engineering increments across payment processing, marketing technology, transactional emails, and backend infrastructure.
3. Optimize Payments and Conversion: Design and optimize payment flows, increase approval rates, and implement event-based data pipelines for analytics and funnel performance.
4. Integrate Conversion Technologies: Configure conversion tracking systems for attribution and funnel optimization, ensuring accurate event data to improve decision-making and drive measurable growth.
5. Ensure Quality: Maintain near-zero critical bugs in production for delivered increments.

• Technical ExpertiseProficiency in JavaScript/TypeScript, including Node.js and Vue.js (SSR, Composition API) and modern backend frameworks.
• Hands-on experience with Google Cloud Platform, serverless applications, and Firebase services.
• Expertise in DevOps practices (CI/CD, GitHub Actions).
• Ownership-Driven ExecutionExtreme bias for action, delivering impactful results in a dynamic environment.
• Takes full ownership of projects and ensures timely delivery.
• Payments and Conversion Tracking ExperienceExperience with PSPs (Stripe, Braintree, other) for subscription billing and dunning flows.
• Proficiency in event-based data pipelines and analytics integrations.
• Knowledge of optimizing conversion tracking (Meta CAPI, Google Ads API, other) and attribution strategies.
• Data-Driven Decision MakingStrong analytical mindset and the ability to leverage data for improving product performance and scalability.
• Problem-Solving & CollaborationExceptional cross-functional collaboration skills to align product, marketing, and engineering teams.
• A proactive approach to troubleshooting and solving complex problems.
• English ProficiencyAdvanced verbal and written communication skills, equivalent to C1 level or higher.
• AI Tools and AutomationProficiency in applying AI tools to accelerate engineering workflows, including AI-assisted code generation for rapid prototyping, debugging, and optimization.
• Experience leveraging AI to automate repetitive tasks, such as refactoring, testing, and deployment.

• Inspiring Mission: Help users live longer, healthier lives through innovative products.
• Impact: Directly influence company growth with minimal bureaucracy.
• Attractive Compensation: Competitive salary and comprehensive benefits package.
• Work-Life Balance: Flexible working hours.
• Professional Development: Tuition reimbursement.
• Remote Work: Fully remote, with a preference for candidates within ±2 hours of CET.
• Comprehensive Benefits: Health insurance, gym membership reimbursement, home office support.

A Sneak Peek into Our Hiring Process

• Initial Conversation (30 minutes). We'll start with a 30-minute chat to get to know you, discuss your background, and understand your experience in full-stack engineering and ownership-driven execution.
• Technical Interview (1 hour). You'll meet with the hiring manager to dive deeper into your technical expertise, focusing on areas like backend architecture, payment flows, MarTech solutions, and event-driven systems.
• Practical Assignment (Homework Task). You'll receive a task designed around real-world engineering challenges. This will help us evaluate your problem-solving skills, technical knowledge, and approach to delivering robust solutions.
• Homework Presentation & Discussion (1 hour). In this final step, you'll walk us through your solution to the assignment, explaining your design decisions, coding approach, and how you leveraged data or AI tools to optimize your solution. No additional preparation is required—just bring your expertise and be ready to discuss your work in detail.