Ingénieur Full Stack/Ingénieure Full Stack

Sanjow is a a european SaaS group specialising in subscription-based digital services across Europe and the UK. Their mission: design robust, optimised, and scalable infrastructures that support rapid growth and foster experimentation. They make life easier for individuals and businesses with turnkey online solutions , particularly in the travel sector — from flight check-ins to airport lounge access, as well as high-volume platforms for ticket purchases. They also operate in other areas such as gift cards and mobile top-ups , while constantly exploring new opportunities, especially in AI . The name Sanjow comes from the combination of the Japanese word for “support” (sanjo) and “flow” — a nod to their DNA of providing smooth, efficient assistance. With headquarters in Paris , an office in Lisbon and colleagues based over the world, Sanjow is a fast-paced international start-up where innovation and collaboration know no borders. The mission To join their new team of 3 developers building their own payment solution , Sanjow is looking for a highly motivated and talented Full Stack Developer (Node.js) . They’re seeking someone with proven expertise — and genuine passion — for the e-commerce sector , hands-on experience in payments and subscriptions , and solid mastery of the Agile SCRUM methodology. This is a small, fast-moving team, so be ready to roll up your sleeves and dive in You’ll work closely with product leadership and technical peers to design, build, and deploy a modern billing system that includes rebill logic, smart routing, retries, and deep integrations with multiple PSPs. Your main missions will be: Architect and develop Sanjow’s Payment Box Implement payment features such as smart routing, retry logic, and direct PSP integrations Collaborate with Product and Data teams to define use cases and KPIs Build and maintain integrations with existing services and APIs Ensure high availability, traceability, and observability of transactions Help define best practices for testing, release cycles, and monitoring Tech Stack: Languages: TypeScript / JavaScript Backend: Node.js, Express, Prisma (NestJS is a plus) Frontend: React, Next.js Database: PostgreSQL, Redis Infrastructure: Render, Vercel, GitHub Methodology: Agile (2-week sprints), CI/CD Why choose Sanjow? Play a key role in one of their most strategic initiatives Enjoy high autonomy and ownership in a lean, fast-paced environment Build critical infrastructure from scratch Benefit from a flexible work culture and flat hierarchy Who they’re looking for: 5+ years’ experience as a developer with strong skills in TypeScript, Node.js , and relational databases Proven experience building payment systems , PSPs, or billing logic Confident building API backends and asynchronous workflows Strong focus on code quality and modular, testable design Autonomous, results-driven, and performance-oriented Fluent in English (Portuguese is a strong plus) Bonus points for : Experience with smart retry logic, subscription lifecycles, or multi-MID routing Familiarity with master gateways such as Rebilly or IxoPay Interest in using AI tools to boost coding and development productivity Recruitment Process Phone call with a recruiter from Eiquem First interview with the CTO Technical interview with the Tech Lead of the payments team Final interview with one of the cofounders