}

                    // Normal polling interval: max 5 seconds, increased based on failures
                    long pollInterval = Math.min(MAX_POLL_INTERVAL, BASE_POLL_INTERVAL + (registration.getHeartbeatFailures() * 500));
                    Thread.sleep(pollInterval);

                } catch (InterruptedException e) {
                    log.debug("Async notification monitoring interrupted for {}", registrationId);