Developed and evolved high-throughput backend microservices in Clojure powering Nubank's payment authorization platform, processing millions of financial transactions across Brazil, Mexico, Colombia, USA, and Switzerland. Designed and implemented backend features supporting payment authorization for millions of daily financial transactions. Designed scalable backend services using functional programming principles, microservices, and event-driven architecture to support mission-critical payment workflows. Collaborated with Product Managers and cross-functional engineering teams to translate business requirements into technical solutions. Participated in code reviews, pair programming, technical design discussions, and on-call rotations to continuously improve software quality supporting high-availability payment systems serving over 100 million customers. Led the backend engineering execution of the Colombia Debit launch, coordinating technical delivery across Fraud, Cards, Authorization, and Debit teams. Built and maintained cloud-native backend services deployed on AWS, leveraging Kafka, DynamoDB, Kubernetes, and CI/CD pipelines to support highly available payment systems.