Received same action(s) within redux will be executed first and then one(s) in epic(s) of redux-observable if there are common action(s) existing in redux and redux-observable.[1] Figure 1. Excerpt statement from redux-observable official site [2] Figure 2. Order sequence diagram for redux-observable. Photo credit to Brian Leathem [3] Redux store is action-in and state-out. Redux-observable is action-in and action-out. Behavior of redux means it generate out new centralize-management state tree