Tracking Active Requests: Design Lessons from Payment Systems and HTTP/2

Effective in-flight request tracking is essential for building reliable distributed systems that handle concurrent operations without losing or duplicating requests. By examining proven patterns from payment processing and HTTP/2 protocol design, developers can implement robust request lifecycle management that improves system observability and resilience. These lessons are particularly valuable for teams developing asynchronous systems where properly tracking active operations directly impacts failure detection and prevents silent data loss.