Software Developer

Software Developer If you are a senior software developer, passionate about digital transformation, and would like to work in a dynamic SaaS environment, we would love to hear from you. 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. Department Technology Locations Sabadell-Spain Remote status Hybrid Seniority Level Entry Level LinkedIn Company Name B2BRouter About B2BRouter B2Brouter simplifies electronic invoicing and document exchange for businesses of all sizes. Our cloud-based platform helps companies connect with public administrations and private companies ensuring compliance and saving time through fully digital and secure processes. Founded in 2003 Coworkers 50