The shape
A queue separates the service that creates work from the service that performs it. Producers can continue during a short burst while consumers catch up.
The useful question
What is the delivery contract? At least once delivery can repeat work. Exactly once behavior usually means carefully scoped deduplication and transactions, not a magical broker switch.
Stress test
Slow consumers while producers remain steady. Backlog size, oldest message age, and processing rate show whether the system is recovering.
Tradeoff
Ordering often limits parallelism. Partitioning by a key preserves local order while allowing independent keys to progress at the same time.