Senior Backend Engineer

Owned all backend delivery — setting priorities, defining architecture, deciding release timelines, and managing production deployments across cross-functional teams including frontend. Led the end-to-end delivery of a B2B partner platform enabling authentication and booking requests, coordinating frontend work and shipping reliably to production in 2 months. Designed a multi-directional payment simulator across a 10-microservice ecosystem, enabling real-time charge/refund calculations for both back-office and client-facing applications. Reduced API response times by ~30% through systematic refactoring — eliminating redundant database calls, introducing bulk transaction operations, and leveraging Node.js asynchronous patterns. Achieved zero registered downtime across all releases. Built API endpoints exposing the full payment lifecycle — charges, refunds, request data — to the data team, enabling ML-powered product features. Mentored junior engineers on REST API design, SOLID principles, and effective use of AI coding tools. Established Git procedures, code review standards, and CI/CD pipelines across the team. Contributed to product decisions beyond implementation — participating in roadmap discussions with operations and market management, running regular stakeholder syncs, and proactively proposing tech agenda topics to improve products and processes across a cross-functional team spanning backend, frontend, mobile, and data.

Developed and enhanced a multi-jurisdictional compliance and risk management system, building AML risk scoring algorithms and enhanced due diligence workflows to secure over $2B in cryptocurrency transactions. Built real-time sanctions screening services and critical fraud prevention features, embedding security-first design into core transaction flows. Managed full-cycle third-party integrations — from API research and technical spikes to production deployment — ensuring reliable data flow and system interoperability. Represented the backend team in a company-wide infrastructure modernization to Kubernetes, improving application performance and reducing operational costs.

Built a microservices ecosystem using RPC over HTTPS with asynchronous messaging (NATS), enabling high-volume inter-service communication and system resilience. Implemented integrations for Property Management Systems, Payment Gateways, and Digital Lock providers, using a stateless agent as an Anti-Corruption Layer to protect core business logic.

Developed and shipped end-to-end features for a Portuguese government platform serving 10M+ citizens, facilitating social security and financial assistance benefits processing. Built a personal loan application system from scratch for a major Spanish bank, implementing an optimized workflow that enabled same-day loan approval and fund disbursement.