As a senior backend engineer on Booking.com's Financial Reconciliation Team, designed and delivered a high-throughput microservice handling daily settlement reconciliation between Booking.com and global accommodation partners. The system processed millions of daily transactions, managing refund synchronization, commission verification, and partner payment record alignment using an event-driven architecture built on Kafka, Spring Boot, and MySQL, with real-time observability via Prometheus, Grafana, and Elasticsearch.