So, recently I got rejected in a Salesforce interview for this question. If we think on this, we will say that pub/sub falls under fire & forget Integration pattern. However, I read it as being marked as a separate pattern in below trailhead module. https://trailhead.salesforce.com/en/content/learn/modules/app-integration-patterns/app-integration-patterns-2

So, I concluded on the basis of this, that it should fall under a separate pattern as here the producer is not aware of the subscriber and there is no acknowledgment sent to the producer. However, when I said the same to the interviewer, he argued with me and seemingly rejected me for this (as checked with HR). I am not saying this as the only reason but as one of the reasons.

Can anyone help me to understand it better or share your view?

If you check below documentation, Salesforce itself has not named it. So, I am confused... https://developer.salesforce.com/docs/atlas.en-us.integration_patterns_and_practices.meta/integration_patterns_and_practices/integ_pat_data_virtualization.htm


1 Answer 1


The issue here is that comparing F&F to PubSub is not an "apples-to-apples" comparison. In order to compare two or more things, they should generally be from the same taxonomical parent and have the same taxonomical rank. The answer is simultaneously that F&F and PubSub are the same thing, and yet they are two different things. They share identical characteristics at the "algorithm class" taxonomy level, but there's no way to compare them at the "algorithm" level, because they are in two different taxonomy ranks.

I think the best "correct" answer to such a question is that the question is invalid, because it is incorrect to compare the two directly. Alternatively, you could say that PubSub is an implementation of F&F, so the differences are simply that one is an implementation of an algorithm.

Think about the following hypothetical questions:

  • What's the difference between a vehicle and a car?
  • What's the difference between a laptop and a Lenovo laptop?
  • What's the difference between a rhino and a house?

As you can see, when you don't have an apples-to-apples comparison, the questions simply don't make sense (though, arguably, the last one sounds like a setup for a joke).

As such, in the future, you should take care to avoid such invalid comparisons and point them out. It's entirely possible the interviewer also didn't realize the problem with the question, either, or it might have been a test of logic to see if you could figure out that the question was invalid.

  • Thanks for the explanation. I think it's an unfair comparison. In the broader bucket, it should be F&F but still, it has few capabilities of its own which stand it out... About the interview question, I think it was a bad day. Interviewer having pre-conceived answers to subjective questions is not healthy for the overall candidate assessment. Jun 25, 2022 at 13:57

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .