Layer 2 Ecosystem
Overview of L2 solutions — Arbitrum, Optimism, Base, zkSync, Starknet.
Layer 2 (L2) is an ecosystem solving Ethereum scalability — hundreds of thousands of TPS, fees of fractions of a cent, but with Ethereum mainnet security.
Leading Optimistic Rollups:
•Arbitrum One — largest L2 by TVL, GMX, Camelot DEX
•Optimism — Coinbase Base parent, Synthetix, Velodrome
•Base — Coinbase L2, large retail adoption, dApp ecosystem
Leading ZK Rollups:
•zkSync Era — EVM compatible, native account abstraction
•Starknet — Cairo language, Cairo VM (not EVM)
•Scroll — community focused, EVM equivalent
•Polygon zkEVM — Polygon ZK solution
Difference Optimistic vs ZK:
•Optimistic: transactions assumed valid, 7 days for challenge
•ZK: mathematical proof of validity for every batch (no waiting)
•ZK better long-term, Optimistic faster to deploy
L2 bridges:
•Official bridge — secure but slow (Optimism: 7 days to withdraw)
•Third-party bridge — faster, but bridge risk (Stargate, Across)
L2 airdrop farming: Arbitrum ARB, Optimism OP were distributed retroactively.