frontend-network-resilience

Exponential backoff retry increases wait time between failed requests using a formula like delay = baseDelay * (multiplier ^ attempt). Implement a retryWithBackoff function that catches errors, increments attempt counts, and reschedules requests with growing intervals—commonly used for transient failures like timeouts or rate limits.

Offline detection uses navigator.onLine to check connectivity status and listens to online/offline events. When offline is detected, queue requests, show appropriate user messaging, and resume automatically when connectivity returns, enabling graceful degradation without losing user data.

Classify errors into categories—offline, timeout, blocked, server_error—by examining response status, error type, and navigator state. Map each category to specific user feedback so users understand why an operation failed and what happens next, reducing frustration during network issues.

Non-idempotent operations (POST, DELETE without unique keys) risk duplicate effects if retried blindly. Handle this by tracking request IDs, implementing server-side deduplication, or using error-type differentiation to skip retry on success-with-error responses, ensuring safe automatic recovery.

Use progressive loading indicators—spinners, progress bars, status messages—that update as retry attempts occur and backoff delays elapse. Inform users of retry count and estimated wait time so they understand the system is working, not frozen.