Ready to build systems that power complex products at scale?¿Quiere presentar una candidatura? Asegúrese de que su CV está actualizado y luego lea atentamente las siguientes especificaciones del puesto antes de solicitar.We're hiring a 2 Senior Back-end Software Engineer to design and scale core backend systems that transform complex components into structured, sellable solutions. You'll work on high-impact challenges around scalability, pricing, payments, and AI-driven automation, directly influencing revenue, operations, and customer experience.About the company: International travel scale-up building technology to design, price, and sell complex trips at scale through automation and AILocation: 100% Remote in Spain with adaptable scheduleSalary: 55k-70k (according to seniority)Benefits: Compensation on transportation, food, private health insuranceKey ResponsibilitiesDesign and scale backend systems and APIs for complex, high-impact productsBuild solutions that enable product configuration and transformation into sellable offeringsDevelop and optimize pricing, payments, and financial flowsEnsure system reliability, scalability, and performance across distributed systemsBuild internal tools for Product, Finance, and Operations teamsCollaborate with stakeholders to define problems and drive solutions end-to-endLeverage AI tools and automation to improve efficiency and workflowsWhat We're Looking For4+ years of experience building scalable backend systemsStrong experience with PHP, Node.js, C# or similarSolid understanding of distributed systems and event-driven architectures (EDA)Experience designing and integrating REST APIsProduct mindset focused on impact, not just deliveryExperience with CI/CD, testing, and clean architecture principles (DDD)Strong communication skills in cross-functional environmentsNice to have: Experience with AI/LLMs, automation workflows, observability (logging, monitoring, tracing), or frontend technologies (React)Ready to take the next