Asynchronous Backing

Asynchronous Backing

Asynchronous Backing decouples parachain block production from relay chain block production. Previously, a collator had to wait for the relay chain to accept or reject a candidate block before building the next one. Async backing allows collators to produce candidate blocks continuously, without waiting, and have multiple candidates in-flight simultaneously.

This change introduces a new protocol for candidate submission and acceptance, along with adjusted timing parameters that let parachains produce blocks faster than the relay chain’s six-second interval. The result is significantly lower latency and higher throughput for parachain block production.

Where it fits: Async backing is a core protocol change in the parachain consensus pipeline. It improves the throughput and responsiveness of all parachains by removing a sequential bottleneck in block production.

Learn more: Official Polkadot Docs