Note the following behaviors of the asynchronous execution:
If you are using multiple post functions, there is no guaranteed order in which they are performed. They might be executed in a different order from the one you set up in Jira's workflow configuration. Therefore, you cannot rely on any result of a previous post function. Also, the order in which the post functions are executed might be different every time the transition is performed.
If a post function encounters a problem (due to misconfiguration or the current data of a Jira issue), the transition (and all other post functions) will be performed regardless of the problem.
The result of a post function might not be visible immediately in the browser.
There are no error messages displayed to the user.