A while back I was on team building a non-critical, low volume application. It just involves people sending a message basically. (there is more too it).
The consultants said he had to use Kafka because the messages could come in really fast.
I said we should stick with Postgres.
No, they said, we really need Kakfa to be able to handle this.
Then I went and spun up Postgres on my work laptop (nothing special), and got a loaner to act as a client. I simulated about 300% more traffic than we had any chance of getting. It worked fine. (did tax my poor work laptop).
No, we could not risk it, when we use Kafka we are safe.
Took it to management, Kafka won since Buzzword.
Now of course we have to write a process to feed the data into Postgres. After all its what everything else depends on