Companion

No retries: every failure dead-letters immediately.

Exponential backoff with multiplicative jitter. Delay for attempt n is base * factor^(n-1), capped at max, then scaled by a random factor in [1 - jitter, 1 + jitter]. Gives up after maxAttempts attempts.

Explicit interval list: attempt n waits delays[n - 1], and the job dead-letters once the list is exhausted. intervals(listOf(30.seconds, 2.minutes, 10.minutes)) means up to 4 attempts total. Takes a List because Kotlin prohibits vararg parameters of value-class types such as Duration.