Javier Villanueva, Developer in Bournemouth, United Kingdom
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Javier Villanueva

Verified Expert  in Engineering

eCommerce Developer

Bournemouth, United Kingdom
Toptal Member Since
September 17, 2021

Javier is a full-stack developer with over ten years of experience delivering high-quality web applications and specializing in blockchain development and eCommerce. Javier has worked on multiple popular Web3 projects, and he is familiar with writing smart contracts and front-end integrations based on different blockchains.


Node.js, React, Remix, Next.js, Web3, Ethers.js, TypeScript, Ethereum, Solidity
NF2 Limited
JavaScript, React, Vue, Web3.js, Solidity, Ethereum, DApps, Node.js, PHP...
Media Lounge
PHP, JavaScript, React, Vue, MySQL, Magento, Magento 2, BigCommerce, Shopify...




Preferred Environment

Visual Studio Code (VS Code), iTerm2, GitHub, Bitbucket, Node.js, Postman, Docker, MacOS, React

The most amazing...

...thing I've developed is the dashboard for a Web3 service that allows people to manage gas-less implementation of games and gamified apps in multiple blockchains

Work Experience

Senior Front-end Developer

2022 - PRESENT
  • Developed the front-end interface for the company's back-end systems that interact with multiple EVM-based blockchains in real time.
  • Optimized and maintain the back-end endpoints to maintain provided user services.
  • Provided technical support for developers and gaming agencies using the system and addressed any suggested issues and improvements.
  • Developed the front-end infrastructure for the sandbox game that was built in-house to allow players to manage their worlds, collectibles, currencies, avatars, etc. All are powered by MetaFab systems and blockchain infrastructure.
Technologies: Node.js, React, Remix, Next.js, Web3, Ethers.js, TypeScript, Ethereum, Solidity

Senior Full-stack Developer

2022 - PRESENT
NF2 Limited
  • Programmed the front and back ends of web applications, using mainly custom PHP frameworks like Laravel and WordPress.
  • Developed Web3 decentralized applications based on Ethereum smart contracts using Solidity and JavaScript.
  • Generated product installation and support documentation.
  • Provided training courses on best practices for eCommerce development.
  • Created requirements documents based on the client's needs.
Technologies: JavaScript, React, Vue, Web3.js, Solidity, Ethereum, DApps, Node.js, PHP, Laravel, WordPress, eCommerce

Technical Director

2015 - 2023
Media Lounge
  • Developed and maintained Magento-based eCommerce websites and a site using alternative API-based eCommerce solutions like commercetools.
  • Oversaw the progress of development projects from the technical point of view.
  • Ensured programming-related tasks were completed within budgets and deadlines.
  • Estimated the time and resources necessary to complete requirements.
  • Developed automated processes for quality assurance and testing.
  • Created and managed technical goals for the development team.
  • Monitored and improved internal development processes continuously.
  • Provided technical advice to management and staff outside the development team.
Technologies: PHP, JavaScript, React, Vue, MySQL, Magento, Magento 2, BigCommerce, Shopify, Commercetools, Node.js, Team Management, eCommerce, Quality Assurance (QA), QA Testing, Automated Testing

Blockchain Developer

2021 - 2022
Dino Babies
  • Developed smart contracts for an NFT minting project and optimized for low gas costs.
  • Built a marketplace to allow spending custom ERC20 token to purchase digital items.
  • Advised an internal dev team on structure and implementation of new features to ensure all requirements are met.
Technologies: React, Ethereum, Ethers.js, REST, Amazon Web Services (AWS), Blockchain, Ethereum Smart Contracts

Blockchain Developer

2021 - 2022
Blockchain Media Pty Ltd
  • Developed a collectible NFTs website powered by the Polygon network and using gasless meta-transactions to reward Discord referrals with seasonal ERC1155 tokens.
  • Built a new website for the NFT project using React/Next.js and Ether.js to handle Web3 integrations.
  • Created Discord Bots to track referral invites and reward them in real time with custom NFTs.
  • Assisted in developing smart contracts to allow for meta transactions and optimizations to handle thousands of transactions per minute.
Technologies: Ethers.js, Ethereum, Web3.js, Node.js, React, Sequelize, Solidity, Discord, Discord Bots, X (formerly Twitter) API, Next.js, Blockchain, Ethereum Smart Contracts


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.

Cambria | Duel Arena

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.

MetaFab Dashboard

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.

Ape Invaders

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.

Lazy Lions Collectibles

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.

Lazy Lion's Glitch Army

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.

Sourcery DAO

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.

Dino Babies Shop

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.

Wealthy Ape Social Club

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.

Monke Verse

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.
2003 - 2009

Bachelor's Degree in Computer Science

The Center Technological University (UNITEC) - Valencia, Venezuela


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Adobe Commerce Front-end Developer



Node.js, RequireJS, React, Vue, Web3.js, REST APIs, X (formerly Twitter) API


GitHub, Bitbucket, Postman, Sequelize, Sentry, MetaMask, Prisma, Etherscan


Knockout (Knockout.js), Tailwind CSS, Zend Framework, Laravel, Nuxt.js, Next.js, Remix, Svelte, Express.js, Phaser.io, Chromium Embedded Framework (CEF)


PHP, JavaScript, HTML, CSS, XML, Less, HTML5, Solidity, C++, TypeScript, Rust


Object-oriented Programming (OOP), REST, Automated Testing


Magento, Magento 2, Visual Studio Code (VS Code), BigCommerce, Shopify, Commercetools, Ethereum, Blockchain, Docker, Storyblok, Algolia, WordPress, MacOS, Heroku, Amazon Web Services (AWS), Google Cloud Platform (GCP)


MySQL, PostgreSQL, Amazon DynamoDB


APIs, eCommerce, Front-end Development, IT Project Management, Web Security, DApps, iTerm2, Non-fungible Tokens (NFT), Ethereum Smart Contracts, IT Audits, Team Management, Quality Assurance (QA), QA Testing, Ethers.js, Cloudflare, Smart Contracts, Discord, Discord Bots, ERC-20, ERC-721, Decentralized Autonomous Organizations (DAO), Web3, wagmi, Cryptocurrency Wallets, Voxel

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