Javier Villanueva

HYTOPIA is a modern games platform that powers voxel-based creator experiences. I helped implement the front ends for all their services that required interaction with ETH Mainnet, Polygon, and their custom L2 Blockchain based on Arbitrum Orbit; this included token swaps, staking, bridges, faucets, and many more. I also helped develop user interfaces for their Rust-based game using the Chromium Embedded Framework.

An online multiplayer game where players can challenge each other and stake crypto in battles where the winner takes all. I was primarily responsible for implementing the Web3 integrations between the Phaser game and the wallets/smart contracts using a combination of Svelte, TypeScript, and multiple open source libraries. I also helped implement in-game features and optimize performance to support multiple concurrent players running without slowdowns or lag.

A back-end dashboard for gaming agencies and developers to interact with the MetaFab that provides a self-serve solution for games and gamified apps to integrate powerful blockchain infrastructure.

I developed the dashboard using React and the Remix framework while ensuring the application was performant and easy to use. I implemented best practices like streaming data and the React Suspense API to provide a smooth user experience, although data transfer was often very high.

A P2E NFT game built in the Ethereum blockchain.

I developed the smart contract to mint ERC721 tokens gas-efficiently and allowed staking and rewards. I used off-chain elements to avoid paying gas fees and created a marketplace where items can be bought using the project custom token.

A seasonal NFT collection that rewards Discord referrals with custom ERC1155 tokens. I was responsible for building the front-end and Web3 integration with the Polygon smart contracts. I worked on the functionality that allows for gasless transactions and meta-transactions so the dApp can scale to thousands of transactions per minute.

A unique NFT gamified minting experience built on Ethereum Mainnet where people could purchase and "absorb" other NFTs in the collection; the more NFTs they owned, the more points they would get. I was in charge of developing the front-end Next.js application following the design system in place and integrating it with the smart contract using the Viem and Wagmi React libraries.

A decentralized autonomous organization (DAO) for projects where you can apply for funding to promote unicycling initiatives. I created the smart contract to handle registration and voting for projects and the website and front-end interface to make interacting with it more user-friendly.

The smart contract is integrated with third-party systems that allow notifying users via email when projects are submitted, accepted, or rejected by monitoring events live in the blockchain.

An NFT project shop that allows holders to purchase virtual items with their custom ERC20 token. I helped develop the front end for the shop page and added the integration to transfer tokens to purchase each individual item. The back end uses an AWS DynamoDB to manage listings.

An app to allow ERC721 holders to stake their tokens and earn a custom ERC20 token to be able to spend in the marketplace. I developed the staking contract and the ERC20 token implementation, and the front end Web3 integration using Nuxt and Ethers.js. The staking contract is upgradeable using the UUPS proxy pattern, so it's easier to change in the future.

An NFT collection based on the Ethereum blockchain. I wrote the smart contracts using ERC721 standards and developed the website's front end to allow people to mint using multiple wallets. I also set up the server infrastructure that could handle over 28 million requests at one point within a few hours while maintaining 100% uptime.