BAC-L1-DOT-103Polkadot
BABE and GRANDPA: production and finalisation
Two distinct mechanisms, routinely confused: one picks who produces a block, the other decides when a block becomes irreversible.
- Level
- L1 — Blockchain developer
- Duration
- 3 h
- Track
- Polkadot
- Maintainer
- Polkadot / Substrate Lead Architect
Learning objectives
- 01Explain proposer selection by verifiable lottery
- 02Describe finalisation as a process separate from production
- 03Interpret the gap between best block and finalised block
Guided lab
Watch the production/finalisation gap live on a test network and correlate it with network conditions.
Independent lab
Document how finalisation behaves when a share of validators becomes unreachable.
Security angle
What an application must never do before finalisation, and the cost of ignoring that rule.
Assessment
Observation report with timestamped measurements.