Senior Backend Engineer

Senior Backend Engineer

Pluxee

Madrid, Spain

What You’ll Do

• Design Integration-First Systems: Design and evolve backend services and APIs that enable secure, reliable, and scalable integrations with customer and partner systems (HRIS, payroll, benefits providers, etc.).
• API & Contract Ownership: Define, version, and maintain API contracts (REST, async events), ensuring backward compatibility and a smooth developer experience for external consumers.
• Handle Real-World Complexity: Build systems that gracefully handle partial failures, retries, idempotency, rate limiting, and inconsistent external data.
• Event-Driven & Distributed Architectures: Evolve existing synchronous flows into scalable, event-driven architectures that support growing integration needs across multiple markets.
• Quality & Reliability at the Edge: Ensure high test coverage (unit, integration, contract tests) and validate integrations through sandbox environments, mocks, and automated validation pipelines.
• Operational Excellence & Observability: Monitor integration health in production, detect anomalies, and troubleshoot issues across system boundaries using logs, metrics, and traces.
• Technical Leadership: Lead by example through strong code reviews, mentoring, and documentation. Help define integration standards, best practices, and reusable patterns for the squad and beyond.

Our Technical Stack

• Backend Core: Node.js (TypeScript), NestJS (or similar frameworks).
• APIs & Integrations: REST APIs, SFTP, Async messaging patterns.
• Data & State: MongoDB, PostgresSQL, ClickHouse.
• Infrastructure: AWS, Docker, Kubernetes, GitLab CI/CD.
• Observability: Datadog.

You’re a Match If You Have a Few of the Below

• Proven Senior Expertise: 3+ years of experience building and maintaining production-grade backend systems, ideally in the Node.js ecosystem.
• The “Integrations Mindset”: Hands-on experience building APIs or partner integrations. Familiarity with external system constraints, SLAs, and contract-driven development.
• Distributed Systems Knowledge: Strong understanding of idemptecy, retries, eventual consistency, race conditions, and failure handling across system boundaries.
• Customer-Centric Engineering: You care about developer experience, clear documentation, predictable behavior, and making integrations easy to adopt and operate.
• Quality & Security First: Experience with automated testing strategies and a strong focus on data protection, authentication, authorization, and secure integrations.
• Growth Mindset: Curious, open to feedback, and motivated to continuously improve both your own skills and the team’s engineering culture.