Replacing custom leader election with CometBFT for Byzantine fault tolerance, multi-validator voting, and instant finality.

Adding fault tolerance with Redis leader election, PostgreSQL payload storage, and member nodes that execute blocks on their own Geth.

Building a production-ready single-node consensus layer with retry logic, health checks, graceful shutdown, and metrics.

How to build a custom consensus layer for Geth using the Engine API - the foundation for L2 sequencers and private chains.