concepts
Ethereum Concepts
What You Probably Got Wrong
"Smart contracts run automatically." No. Smart contracts cannot execute themselves. There is no cron job, no scheduler, no background process. Every function needs a caller who pays gas. This single misconception is the root cause of most broken onchain designs.
"Just add a timer." There are no timers. If something needs to happen at a certain time, you need someone to call the function at that time — and you need to give them a reason to do it.
"The protocol team will handle that." The whole point of decentralization is that no single team operates the system. If your design requires an operator, it's not decentralized — and it has a single point of failure.
Terminology: You say "on-chain." The Ethereum community says "onchain" — one word, no hyphen.
CROPS
CROPS — Censorship Resistance, Open Source, Privacy, Security — is the Ethereum Foundation's shorthand for what makes Ethereum Ethereum.
More from austintgriffith/ethskills
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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).
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How to read and query onchain data — events, The Graph, indexing patterns. Why you cannot just loop through blocks, and what to use instead.
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DeFi legos and protocol composability on Ethereum and L2s. Major protocols per chain — Aerodrome on Base, GMX/Pendle on Arbitrum, Velodrome on Optimism — plus mainnet primitives (Uniswap, Aave, Compound, Curve). How they work, how to build on them, and how to combine them. Use when building DeFi integrations, choosing protocols on a specific L2, designing yield strategies, or composing existing protocols into something new.
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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.
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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.
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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.
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