The ambulance pattern is useful for creating a “fast-path” for requests that need to go ahead of others - just like cars pulling over to let an ambulance through (hence the name of the pattern). In this lesson Mark Richards explains why message priority is not a good way of implementing this pattern, and shows another technique that is much more effective for implementing this pattern.
Reference Links:
Software Architecture Monday: https://bit.ly/3dadEe3
Fundamentals of Software Architecture: https://amzn.to/3rgFLjY
Software Architecture: The Hard Parts: https://amzn.to/3BjMMF2