Ethereum Developer Ethereum Upgrades and Layer 2 Scaling 2 β Questions and Answers
Question 1: What is EIP-4844 (Proto-Danksharding) and its primary benefit?
- It introduces blob-carrying transactions that drastically reduce rollup data posting costs (Correct answer)
- It enables sharded execution across 64 parallel chains
- It adds native account abstraction to Ethereum
- It merges the execution and consensus layers for simplified node operation
Correct answer: It introduces blob-carrying transactions that drastically reduce rollup data posting costs
EIP-4844 introduced a new transaction type carrying data 'blobs' with a separate, cheaper fee market, reducing L2 data costs by up to 10x.
Question 2: What is account abstraction in Ethereum, as proposed by ERC-4337?
- Allowing smart contracts to act as user accounts with custom validation logic for transactions (Correct answer)
- Abstracting private keys away from users with biometric authentication
- Replacing EOAs with multi-sig wallets as the default account type
- Enabling accounts to hold multiple assets without separate contracts
Correct answer: Allowing smart contracts to act as user accounts with custom validation logic for transactions
ERC-4337 enables smart contract wallets with programmable transaction validation, enabling gasless transactions, social recovery, and batch operations.
Question 3: What is the purpose of the `CREATE2` opcode in Ethereum?
- To deploy a contract at a deterministic address based on the deployer, salt, and init code (Correct answer)
- To create two contracts in a single transaction
- To deploy upgradeable proxy contracts only
- To clone an existing contract's bytecode to a new address
Correct answer: To deploy a contract at a deterministic address based on the deployer, salt, and init code
`CREATE2` allows predetermining a contract's deployment address before it exists, enabling counterfactual contract instantiation.
Question 4: What is a state channel in Ethereum layer-2 scaling?
- An off-chain communication channel between parties that only settles the final state on-chain (Correct answer)
- A channel between Ethereum nodes for fast block propagation
- A smart contract that channels funds between DeFi protocols
- A private blockchain that posts merkle roots to Ethereum
Correct answer: An off-chain communication channel between parties that only settles the final state on-chain
State channels allow two or more parties to exchange signed state updates off-chain, opening and closing the channel with on-chain transactions.
Question 5: What does the Ethereum Cancun upgrade (2024) primarily achieve for developers?
- It activates EIP-4844, adding blob transactions that lower rollup fees significantly (Correct answer)
- It enables full sharding across 64 execution shards
- It removes the 7-day withdrawal delay for Optimistic Rollups
- It introduces native token bridging between all L2 networks
Correct answer: It activates EIP-4844, adding blob transactions that lower rollup fees significantly
The Cancun upgrade activated EIP-4844, introducing blob-carrying transactions that dramatically reduced the cost of posting data for L2 rollups.
Question 6: What is the role of a bridge in the Ethereum L2 ecosystem?
- To transfer assets and messages between Ethereum mainnet and layer-2 networks or other chains (Correct answer)
- To index and serve L2 transaction data to dApp frontends
- To aggregate liquidity from multiple L2 DEXes for best swap prices
- To synchronize smart contract state between L1 and L2 deployments
Correct answer: To transfer assets and messages between Ethereum mainnet and layer-2 networks or other chains
Bridges lock assets on one chain and mint wrapped equivalents on another, enabling users to move funds between L1 and L2 or across chains.
Ethereum Developer Ethereum Upgrades and Layer 2 Scaling 2
What is EIP-4844 (Proto-Danksharding) and its primary benefit?