Ledger LandISSUE #90 of 90

references · ethers · viem · web3.js · ercs

BlockyVSDouble-Spend Dan

Blocky saysYou’ve covered blockchain end to end — now build something small and on-chain to make it real.

Blockchain clicks when you build. The capstone: write and test a small contract (an ERC-20 token or a simple escrow) in Solidity, deploy it to a testnet, and connect a front-end with ethers.js or viem to read state and send a transaction. That end-to-end loop — contract, wallet, RPC, UI — is the whole skill. References: the Solidity docs, the EIP/ERC index, ethers/viem docs, and a testnet faucet.

Power-ups you unlock

Build to retain — ship a small contract
Solidity + testnet + ethers.js/viem front-end
The contract↔wallet↔RPC↔UI loop is the skill
Refs: Solidity docs, EIPs, ethers/viem, faucets

Double-Spend Dan attacks — common mistakes

Reading without ever deploying to a testnet
Deploying to mainnet untested
Skipping the front-end integration loop

Boss battlePlan a testnet project: a token contract + a page that shows your balance and transfers.

Example code

<!doctype html><html><head><meta charset="utf-8"></head>
<body style="background:#06040d;color:#e6e0ff;font-family:monospace;padding:20px"><pre>1 write ERC-20 in Solidity + tests
2 deploy to a testnet (faucet for gas)
3 viem/ethers front-end: read balance, send transfer
loop: contract ↔ wallet ↔ RPC ↔ UI</pre></body></html>

▶ Open the interactive comic issue

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