Ethereum · Emergency smart contract delivery · April 2022

Not NASA

Founder Domingo Mattle called with 24 hours left before mint. I delivered the ERC-721 contract, allowlist, sale controls, airdrops, metadata, and three-way payout path in time for launch.

24 hourscontract delivery window

1,093tokens minted

88.23 ETHgross paid-mint receipts

Project file

PeriodApril 2022

Product: A hand-drawn Ethereum membership collection for NOTACOMPANY, the community-run creative studio behind the Not NASA ecosystem.
Delivery scope: ERC-721 contract, Merkle allowlist, presale and public-sale controls, per-wallet allowances, airdrops, IPFS metadata, and three-party PaymentSplitter payouts.
Public evidence: 7public sources3on-chain records

Project constraints

01Only 24 hours remained before the scheduled mint
02Sale, supply, allowlist, and payout rules would become public and irreversible
03Three beneficiaries needed a verifiable on-chain revenue split

The challenge

Replace launch risk with a contract the founder could operate confidently the next day.

Domingo Mattle, founder of Not A Company, brought me into the project with one day left before mint. The collection needed more than a basic ERC-721 deployment: separate presale and public states, allowance-aware Merkle proofs, five-token transaction caps, an airdrop reserve, mutable metadata controls, and automatic payouts across three parties. There was no room for a speculative rewrite after launch, so the contract and the operator sequence had to be understandable under pressure.

Architecture and decisions

Allowance-aware presale

The presale leaf committed both the buyer address and its allowance. The contract verified the Merkle proof and tracked cumulative address-level mints, so an approved wallet could not exceed its assigned allocation across multiple transactions.

Separate sale states

Presale and public minting used independent switches and price variables. The team could open each phase explicitly, adjust the configured price when necessary, and move between launch states without redeploying.

Supply and transaction boundaries

The paid mint path enforced a five-token transaction cap and checked the collection boundary on-chain. A separate owner-only airdrop path reserved the final allocation while applying the same supply ceiling.

Three-way PaymentSplitter

The constructor fixed three beneficiaries at 850, 75, and 75 shares. OpenZeppelin PaymentSplitter made each party’s proportional release independently callable and publicly inspectable instead of depending on manual post-mint transfers.

My role

01
Translated the founder’s launch requirements into a deployable ERC-721 contract inside a 24-hour delivery window.
02
Implemented the Merkle allowlist, address-level allowances, public and presale controls, price setters, transaction caps, and airdrop path.
03
Configured the three-party PaymentSplitter and IPFS metadata controls so payouts and token media remained inspectable after deployment.
04
Supported the launch sequence through mint, with the founder reporting that the release ran smoothly and the contract worked as required.

What changed

A launch-critical contract delivered in 24 hours; 1,093 tokens minted and 88.23 ETH recorded in gross paid-mint receipts.

The contract was ready for the scheduled launch rather than becoming the reason it slipped. Domingo’s review records the delivery constraint directly: with 24 hours remaining, the team called and received a functional, flexible contract in time for a smooth mint. Public Ethereum records now show 1,093 tokens and the verified Solidity source; the repository’s transaction audit attributes 88.23 ETH in gross receipts to 662 successful value-bearing mint calls.

Delivered the complete launch contract within the founder’s 24-hour deadline.
The deployed collection minted 1,093 ERC-721 tokens and remains publicly inspectable.
Successful paid mint transactions sent 88.23 ETH in gross receipts to the contract’s on-chain payout system.

“David always executes on the highest and most professional level. He helped us on multiple projects and always overdelivered. On our latest project, with 24 hours left, we called David and he did the impossible: a fully functional and flexible smart contract in 24 hours. The mint went smoothly and everything worked out perfectly.”