We created a custom NFT series collection smart contract using the JS SDK. It interacts with a custom scavenger hunting smart contract that is hooked up and called via APIs deployed to azure. These APIs are protected using recaptcha and are used to prevent spam / gamifying our contracts.
The NFT contract allows for lazy minting NFTs as part of collections resulting in optimized storage structures and custom collection / allowlist logic when compared with traditional NFT contracts in the NEAR ecosystem.
The two repositories to look at are