FerroDruid is an Apache Druid–compatible OLAP engine in Rust — native queries and SQL against a Druid-shaped API, one binary instead of a JVM cluster. Live on AWS Marketplace.

Measured record (as of 2026-07-10)

Quality gates passed

• Conformance harness that replays upstream-Druid query suites and compares responses against a real Druid — compatibility is asserted by diffing, not by reading docs.
• Covered by the nightly fuzz farm; findings feed the same reproduce → failing test → fix → green loop as every Ferro product.
• Same release gate as the rest of the fleet: adversarial review until two consecutive clean rounds.

Honest limitations

• Druid’s surface is large; conformance coverage is strongest on the query paths the harness replays. Ingestion-side parity (supervisors, exotic extensions) is narrower.
• Published benchmarks against a tuned Druid cluster do not exist yet — no performance multiplier is claimed here.