The Hitchhiker’s guide to Diskless Kafka` proposes a new topic type for Apache Kafka that redirects replication from broker disks to cloud object storage, reducing the total cost of ownership (TCO) by up to 80 percent. This deep-dive into KIP-1150 explains how diskless topics eliminate cross-zone traffic and provide instant elasticity without changing the client or requiring costly migrations. The design is intentionally conservative, keeping the upgrade path straightforward with a single topic flag, while also introducing compaction agents to optimize object storage usage and reduce latency. The proposal aims to build on cloud primitives that already run half the internet, making it a significant improvement for Kafka users in the cloud.