> Kafka / RabbitMQ These are different things, and the fact that they're so often conflated is IMO prima facie that they're misused. If you need a queue, you s

> Kafka / RabbitMQ These are different things, and the fact that they're so often conflated is IMO prima facie that they're misused. If you need a queue, you shouldn't be reaching for Kafka, and vice-versa. > Then maybe something like redis/memcache for quick lookups/caching With proper RDBMS schema, indexing, and queries, these are _very_ frequently not needed. At FAANG scale, sure, but I think most would be shocked at how performant a properly-tuned RBDMS can be. That's of course the problem; RDBMS are incredibly difficult to run optimally at scale, and so the easier solution is to scale them up and slap a cache in front of them. > elasticsearch for indexed search queries Again, probably not needed for most. Both Postgres, MySQL, and SQLite (and I assume others) all have FTS that works quite well. ES is massively complicated to administer.