Summary: Join a technically focused team as a Software Developer to build and maintain a B2B electronic invoicing platform, taking end-to-end ownership of backend systems. Highlights: 1. End-to-end ownership of backend systems for an electronic invoicing platform 2. Opportunity to work in a fast-growing international SaaS company 3. Collaborative and supportive team culture with strong technical ownership **Role Overview** We’re looking to bring a Software Developer (Electronic Invoicing) to join a small, technically focused team building and maintaining a B2B electronic invoicing platform. We work with international standards and integrate with national tax systems worldwide. In this role, you’ll take end\-to\-end ownership of backend systems — from design and implementation to production operations. **About B2Brouter** B2Brouter is a leading European provider of electronic document exchange solutions, specializing in e\-invoicing, e\-procurement, and B2B data integration. We help companies automate, secure, and optimize their electronic transactions through reliable, scalable, and compliant digital platforms. **Key Responsibilities** * Design, build, and maintain REST APIs for invoice processing, document exchange, and third\-party integrations. * Develop and manage asynchronous processing pipelines using background jobs and queue systems. * Build and maintain integrations with external platforms, including government tax authorities and document exchange networks. * Optimize database queries, ensure data consistency, and manage concurrency in high\-throughput environments. * Participate in code reviews, technical discussions, and contribute to backend architecture decisions. * Support production operations, including incident response, monitoring, and troubleshooting. * Write and maintain technical documentation (systems, APIs, integration specs, and operational runbooks). **Required Skills \& Qualifications** * 4\+ years of experience developing with Ruby on Rails in production environments. * Strong experience designing and maintaining RESTful APIs. * Hands\-on experience with background job / queue systems and asynchronous workflows. * Solid SQL knowledge and experience in database performance tuning \& optimization. * Comfortable working with XML\-based formats and transformations (e.g., XML, XSLT) as well as JSON. * Proven ability to work with third\-party integrations and external dependencies. * English proficiency, as technical documentation, standards, and specifications are primarily in English. * Familiarity with modern development workflows: Git and CI/CD. **Valuable / Nice\-to\-Have Skills** * Knowledge of Redis and caching strategies. * Experience with observability tools: logging, monitoring, metrics, alerting. * Understanding of security best practices for APIs (auth, data protection, auditability). * Experience working in high\-availability / high\-throughput backend environments. * Experience in electronic invoicing standards and structured formats (e.g., UBL, CII, Factur\-X/ZUGFeRD, etc.). * Experience integrating with government tax authority systems (clearance/reporting models). **What We Offer** * Opportunity to work in a fast\-growing international SaaS company, building a product used by businesses across multiple markets. * Exposure to European and global digital transformation projects, working with international e\-invoicing standards and integrations with tax authorities. * A collaborative, innovative, and supportive team culture, with strong technical ownership and knowledge sharing.