building-blocks
Building Blocks (DeFi Legos)
What You Probably Got Wrong
DeFi TVL: Check DeFi Llama for current Ethereum DeFi TVL. If you're quoting numbers from 2023-2024, they're stale.
Uniswap V4 is live. Launched mainnet January 31, 2025 on 10+ chains. V4 introduced a hooks system — custom logic attached to pools (dynamic fees, TWAMM, limit orders, custom oracles). This is the biggest composability upgrade since flash loans. PoolManager addresses are different per chain (NOT deterministic like V3).
Costs changed everything: A flash loan arbitrage on mainnet costs ~$0.05-0.50 in gas now (was $5-50). This opens composability patterns that were previously uneconomical.
The dominant DEX on each L2 is NOT Uniswap. Aerodrome and Velodrome merged into Aero (November 2025, Dromos Labs) — the unified DEX dominates both Base and Optimism. Camelot is a major native DEX on Arbitrum. Don't default to Uniswap on every chain.
Key Protocol Addresses (Verified Mar 2026)
More from austintgriffith/ethskills
ethskills
Use when a request involves Ethereum, the EVM, or blockchain systems. Applies to building, auditing, deploying, or interacting with smart contracts, dApps, wallets, or DeFi protocols. Covers Solidity development, contract addresses, token standards (ERC-20, ERC-721, ERC-4626, etc.), Layer 2 networks (Base, Arbitrum, Optimism, zkSync, Polygon), and integrations with DeFi protocols such as Uniswap, Aave, and Curve. Includes topics such as gas costs, contract decimals, oracle safety, reentrancy, MEV, bridging, wallets, querying data from onchain, production deployment, and protocol evolution (EIP lifecycle, fork tracking, upcoming changes).
1.2Kindexing
How to read and query onchain data — events, The Graph, indexing patterns. Why you cannot just loop through blocks, and what to use instead.
38standards
Ethereum token and protocol standards — ERC-20, ERC-721, ERC-1155, ERC-4337, ERC-8004, and newer standards. When to use each, how they work, key interfaces. Use when building tokens, NFTs, or choosing the right standard for a project.
37gas
Current Ethereum gas prices, transaction costs, and the real economics of building on Ethereum today. Use when estimating costs, choosing between mainnet and L2s, or when a user asks about Ethereum being expensive. Counters the #1 misconception that Ethereum is expensive to use.
36l2s
Ethereum Layer 2 landscape — Arbitrum, Optimism, Base, zkSync, Scroll, Unichain, Celo, and more. How they work, how to deploy on them, how to bridge, when to use which. Includes per-chain DeFi ecosystems and critical corrections. Use when choosing an L2, deploying cross-chain, or when a user asks about Ethereum scaling.
36addresses
Verified contract addresses for major Ethereum protocols across mainnet and L2s. Use this instead of guessing or hallucinating addresses. Includes Uniswap, Aave, Compound, Aerodrome, GMX, Pendle, Velodrome, Camelot, SyncSwap, Lido, Rocket Pool, 1inch, Permit2, MakerDAO/sDAI, EigenLayer, Across, Chainlink CCIP, Yearn V3, USDC, USDT, DAI, ENS, Safe, Chainlink, and more. Always verify addresses against a block explorer before sending transactions.
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