+---------+            +---------+
|   API   |- - - - - ->|  Queue  |
+---------+            +---------+
     :
     :
     v
+---------+            +---------+
| Worker  |...........>|  Cache  |
+---------+            +---------+

+---------+            +---------+
|  Retry  |-.-.-.-.-.->|  DLQ    |
+---------+            +---------+
