Ethereum Upgrades and Layer 2 Scaling Flashcards
6 cards from real Ethereum Developer practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Ethereum Upgrades and Layer 2 Scaling flashcards as text
What major change did the Ethereum Merge (2022) introduce?
Answer: Replaced Proof of Work with Proof of Stake consensus
The Merge transitioned Ethereum from energy-intensive Proof of Work mining to Proof of Stake, where validators stake ETH to propose blocks.
What is EIP-1559 and what problem does it address?
Answer: A fee market reform that introduced a base fee burned per transaction, reducing fee unpredictability
EIP-1559 replaced the first-price auction gas model with a protocol-determined base fee that is burned, plus an optional priority tip for validators.
What is an Ethereum layer-2 (L2) solution?
Answer: A protocol built on top of Ethereum that processes transactions off-chain while inheriting mainnet security
Layer-2 solutions execute transactions off the Ethereum mainnet to increase throughput and reduce fees, periodically settling proofs or data on L1.
What is the fundamental difference between Optimistic Rollups and ZK Rollups?
Answer: Optimistic Rollups assume validity and use fraud proofs; ZK Rollups use cryptographic validity proofs
Optimistic Rollups post transactions optimistically and allow a challenge period, while ZK Rollups post cryptographic proofs that are immediately verifiable.
What does 'data availability' mean in the context of Ethereum rollups?
Answer: Ensuring that the transaction data needed to reconstruct rollup state is accessible to anyone
Data availability ensures that the compressed transaction data posted by rollups to Ethereum can be downloaded and verified by any participant.
What is a sequencer in a rollup network?
Answer: A centralized or decentralized node that orders and batches transactions before posting them to L1
The sequencer is responsible for receiving user transactions, ordering them, and periodically posting compressed batches to the Ethereum base layer.