
Oracle design: examine where a protocol gets its facts
Evaluate data sources, update rules, freshness checks, and failure behavior in oracle-dependent applications.

Evaluate data sources, update rules, freshness checks, and failure behavior in oracle-dependent applications.
Learn fee rates, virtual size, input count, and the difference between accelerating and refunding.
Distinguish validation, mining, wallet signing, and storage when deciding what a node accomplishes.
Compare service balances, self-custody, hardware signers, and recovery responsibilities.
Connect proof of work, validation, pool shares, and operating economics without confusing their roles.
Read account behavior without confusing a wallet application, an address, and the authority behind it.
Calculate a hypothetical fee and learn why a reverted transaction can still cost ETH.
Understand head, justified and finalized checkpoints, and why application receipts can arrive before finality.
Learn what deployed code guarantees, what it cannot know, and how upgrades change the trust picture.