Backoff - Nito

On 429, wait at least Retry-After.
On 502/503 without Retry-After, double the wait each attempt (1s, 2s, 4s, 8s).
Add random jitter.
Cap attempts and maximum wait, then surface the error with its X-Request-ID.

Retry-After beats your computed backoff.

Pseudocode

attempt = 0
while attempt < max_attempts:
    response = send(request)
    if response.ok:
        return response
    if not retryable(response.code):
        raise response
    if response.has("Retry-After"):
        wait = response.retry_after_seconds
    else:
        wait = min(base * 2 ** attempt, max_wait)
    sleep(wait + random_jitter())
    attempt += 1

Which codes are retryable: Retry behavior.

Circuit Breaker

After consecutive provider failures the gateway stops routing to that provider for a cooldown window, then probes before reopening. During cooldown you may see 503 unavailable or 502 provider_error; an open-circuit rejection never dispatched, so it is safe to retry with backoff.