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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Backend Engineer - Security Subsystem - **Company:** Banco Santander, S.A. - **Location:** Madrid, Spain - **Contract:** Permanent contract - **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Amazon Web Services, BASIC (Programming Language), Cyber Security, Databases, Data Structures, Software Debugging, Distributed Systems, Amazon DynamoDB, PostgreSQL, Redis, Subsystems, Caching, Backend, Event Driven Architecture, Code Testing, Software Version Control - **Published:** September 9, 2026 - **Apply:** https://www.buscojobs.com.es/senior-backend-engineer-security-subsystem-en-madrid-ID-369201470 ## About the Role Compensaciones / Beneficios * Design, implement, test, deploy and operate backend services and APIs used in security-critical journeys * Translate requirements into maintainable designs and incremental delivery plans with senior engineers and Team Leads * Write clear, well-tested code and improve tests, docs, and developer workflows * Build observability into services using logs, metrics, and traces to understand production behavior * Participate in sustainable on-call rotation, investigate incidents, and drive root-cause analysis * Contribute to data modelling, caching, asynchronous processing, resilience, and performance improvements * Participate in code and design reviews and progressively own larger service areas and decisions Responsabilidades * +4 years of backend experience in Go or Java (Required) * Strong understanding of APIs, data structures, databases, testing, version control, and basic distributed systems (Required) * Experience debugging production or production-like environments (Preferred) * English (Required) * Spanish (Preferred) * APIs, data structures, databases, testing, version control (Required) * Distributed systems concepts, caching, asynchronous processing, resilience, performance (Required) * AWS, Redis, DynamoDB, PostgreSQL, or event-driven architecture (Required) Requisitos principales * hybrid work model * remote within Spain * equal opportunity employer ## Description Experteer Overview In this role you will design, implement, and operate backend services for security-critical customer journeys within a hybrid Madrid or remote setup in Spain.You will work closely with senior engineers and team leads to convert requirements into maintainable designs and incremental deliveries.You'll enhance observability, reliability, and performance while contributing to secure, scalable APIs and data models.This is a chance to shape security infrastructure across products and markets in collaboration with cross-functional teams.Compensaciones / Beneficios * Design, implement, test, deploy and operate backend services and APIs used in security-critical journeys * Translate requirements into maintainable designs and incremental delivery plans with senior engineers and Team Leads * Write clear, well-tested code and improve tests, docs, and developer workflows * Build observability into services using logs, metrics, and traces to understand production behavior * Participate in sustainable on-call rotation, investigate incidents, and drive root-cause analysis * Contribute to data modelling, caching, asynchronous processing, resilience, and performance improvements * Participate in code and design reviews and progressively own larger service areas and decisions Responsabilidades * +4 years of backend experience in Go or Java (Required) * Strong understanding of APIs, data structures, databases, testing, version control, and basic distributed systems (Required) * Experience debugging production or production-like environments (Preferred) * English (Required) * Spanish (Preferred) * APIs, data structures, databases, testing, version control (Required) * Distributed systems concepts, caching, asynchronous processing, resilience, performance (Required) * AWS, Redis, DynamoDB, PostgreSQL, or event-driven architecture (Required) Requisitos principales * hybrid work model * remote within Spain * equal opportunity employer ## Related Videos - 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