I’m lost at why a DB (Cassandra) with better write performance than read performance was ever selected for a messaging system. I feel like it’s obvious that a message will be read more than it is written (once).
The fact that it has better write speed than read speed doesn't mean that it has bad read speed. It just happens to have even better write speed.
It's like how I connect my phone to my home's cable connection to send a big file. It is better at downloading than uploading, but that doesn't mean it's not the best solution for uploading.
It's like how I connect my phone to my home's cable connection to send a big file. It is better at downloading than uploading, but that doesn't mean it's not the best solution for uploading.