We Ditched RabbitMQ for Kafka 4.0 and Cut Our Message Processing Latency by 55%

After 18 months of battling 2.1-second p99 message processing latency with RabbitMQ 3.12, our team migrated to Kafka 4.0 and slashed that metric by 55% to 945ms, while reducing infrastructure costs by 32% in the first quarter post-migration. This isn't a marketing pitch—it's a data-backed breakdown of why we made the switch, how we executed the migration without downtime, and the exact benchmarks that prove Kafka 4.0's performance gains for high-throughput, low-latency workloads. We initially ch