Andres Felipe Velasquez Trujillo — Blockchain Engineer | Smart Contract Solidity | Full Stack Web3 Developer | Mathematician

Expertise in Smart Contract (3.5 yr.), Full Stack Web (4.0 yr.).

Last verified on May, 2026

Core Skills

Foundry

3 yr.

Bio Summary

Blockchain engineer with 3+ years in Solidity smart contract development, DeFi protocol architecture, and secure decentralized applications using Foundry, Hardhat, and Slither.
Proficient in full stack Web3 development with React, TypeScript, wagmi, viem, and RainbowKit for seamless wallet integrations and user flows.
Experienced in building financial and NFT platforms integrating ERC20/ERC721 standards, Chainlink oracles, and IPFS for decentralized data storage.
Strong background in mathematics and computer science education
Skilled in rigorous testing methodologies including fuzz, invariant, and stateful testing to ensure smart contract security and protocol reliability.

Technical Skills

Programming Languages	Basic, JavaScript, Python, Ruby, Solidity, TypeScript
JavaScript Libraries and Tools	Ethers.js, React Native, Redux-Saga, Web3.js
JavaScript Frameworks	Express, React
Ruby Frameworks	Ruby on Rails
Security	Security
Databases & Management Systems / ORM	Sequelize, Supabase
UI Frameworks, Libraries, and Browsers	CSS, Material UI, Socket.io, Tailwind CSS
Azure Cloud Services	Azure Key Vault
Industry Domain Experience	Blockchain, Healthcare
SDK / API and Integrations	API, RESTful API
Blockchain and Decentralized Software	Binance, Brownie, Chai, Chainlink, DeFi, ERC-20, Ethers.js, Foundry, Hardhat, IPFS (InterPlanetary File System), MetaMask, NFT, OpenZeppelin, RainbowKit, Smart Contract, Stellar, Truffle, Web3
Methodologies, Paradigms and Patterns	Flows
QA, Test Automation, Security	Integration Tests, Mocha, Unit Testing
Mail / Network Protocols / Data transfer	JSON-RPC
Soft Skills	Leadership
Project Management & Administration	Problem Solving
Virtualization, Containers and Orchestration	Storage
Other Technical Skills	computer science, Financial Services, Fuzz, InterPlanetary File System, Mathematics, Payment, Slither, Viem, WAGMI

Work Experience

Full Stack Web3 Blockchain Engineer - Investment Armendariz (Institutional DeFi Protocol)

Duration: Aug 2025 - Present
Summary:

A DeFi platform focused on governance systems, vault infrastructure, treasury management, and on-chain operational controls
The project aims to provide secure and scalable decentralized financial services with modular protocol components

Responsibilities:

Develop Solidity smart contracts and modular protocol components using Foundry-based workflows.
Implement frontend architecture with React, TypeScript, TailwindCSS, wagmi, viem, and RainbowKit.
Design and improve Web3 hooks, wallet integrations, and user flows for protocol interaction.
Build and maintain testing coverage including unit tests, fuzz testing, stateless testing, and stateful/invariant testing.
Run security analysis with Slither and Aderyn, applying secure Solidity practices and improving protocol maintainability and scalability.

Technologies: Solidity, Foundry, React, TypeScript, TailwindCSS, wagmi, viem, RainbowKit, Slither, Aderyn

Full Stack Developer - Vita Wallet (Vita Wallet)

Duration: Aug 2021 - Nov 2025
Summary: Financial applications development including web and mobile features, integrating third-party services and APIs such as Binance, blockchain services, payment platforms, banks, and international payment providers to enhance platform stability and scalability.
Responsibilities:

Implemented web and mobile features using Ruby, Ruby on Rails, React, React Admin, React Native, and JavaScript.
Integrated third-party services and APIs including Binance, blockchain services, payment platforms, banks, and international payment providers.
Maintained and optimized existing application code to improve platform stability and scalability.
Developed unit and integration tests to validate security, reliability, and correct behavior across financial workflows.

Technologies: Ruby, Ruby on Rails, React, React Admin, React Native, JavaScript

JavaScript Instructor / Teaching Lead - Coderhouse (JavaScript Instruction and Cohort Leadership)

Duration: Nov 2021 - Jun 2024
Summary: Delivered remote JavaScript classes and coordinated tutors to support and guide over 5,000 students through JavaScript and programming fundamentals using synchronous and asynchronous learning activities.
Responsibilities:

Delivered remote JavaScript classes through synchronous and asynchronous learning activities.
Planned and taught classes, coordinated tutors, and supported student learning processes.
Led cohorts and tutor teams, guiding more than 5,000 students through JavaScript and programming fundamentals.

Technologies: JavaScript

Full Stack Developer Solidity - Freelance / Independent (Blockchain Healthcare Platform)

Duration: Apr 2022 - Aug 2022
Summary: A blockchain-based healthcare system using Solidity smart contracts to manage subscription services and laboratory services, integrating an ERC20 platform token to facilitate transactions within the healthcare ecosystem.
Responsibilities:

Built blockchain-based healthcare system using Solidity smart contracts, React, Ethers.js, and MetaMask JSON-RPC connectivity.
Implemented administrator-created basic services and laboratory-created specialized services through subscription smart contracts.
Created an ERC20 platform token using OpenZeppelin standards.

Technologies: Solidity, React, Ethers.js, MetaMask, OpenZeppelin, Truffle, Web3.js, Chai, CSS, Material UI

Full Stack Developer Solidity - Freelance / Independent (Rocket Punk NFT Platform)

Duration: Feb 2022 - Mar 2022
Summary: An NFT platform enabling users to mint unique NFTs and transfer ownership on-chain, implementing ERC721 standards for secure and standardized NFT management.
Responsibilities:

Developed an NFT platform where users can mint unique NFTs and transfer ownership on-chain.
Implemented ERC721 standards through OpenZeppelin, Solidity, Hardhat, Web3.js, Chai, React, MetaMask, and CSS.

Technologies: Solidity, OpenZeppelin, Hardhat, Web3.js, Chai, React, MetaMask, CSS

Full Stack Developer Solidity - Freelance / Independent (Decentralized Voting System)

Duration: Jan 2022
Summary: A blockchain voting application designed to provide transparent and immutable election records with candidate registration and one-vote-per-user participation.
Responsibilities:

Implemented a blockchain voting application for candidate registration and one-vote-per-user participation.
Integrated Solidity, Hardhat, Ethers.js, Chai, React, MetaMask, IPFS, and OpenZeppelin for transparent and immutable election records.

Technologies: Solidity, Hardhat, Ethers.js, Chai, React, MetaMask, IPFS, OpenZeppelin

Full Stack Developer Solidity - Freelance / Independent (Lottery DApp)

Duration: Dec 2021
Summary: A blockchain lottery application that stores participation on-chain and selects a random winner, implementing ERC20-style reward logic to incentivize participation.
Responsibilities:

Built a blockchain lottery application that stores participation on-chain and selects a random winner.
Implemented ERC20-style reward logic using Solidity, Hardhat, Ethers.js, Chai, React, MetaMask, and CSS.

Technologies: Solidity, Hardhat, Ethers.js, Chai, React, MetaMask, CSS

Full Stack Developer - RocketXChange (RocketXChange)

Duration: Jul 2021 - Aug 2021
Summary: A blockchain exchange platform connecting users to the Stellar network to exchange fiat and cryptocurrency assets, enhancing cross-asset liquidity and user experience.
Responsibilities:

Created a blockchain exchange platform connecting users to the Stellar network to exchange fiat and cryptocurrency assets.
Implemented JavaScript, React, Redux, Node.js, Express.js, Supabase, Material UI, CSS, Socket.IO, Stellar SDK, and OCR-based functionality.

Technologies: JavaScript, React, Redux, Node.js, Express.js, Supabase, Material UI, CSS, Socket.IO, Stellar SDK

Education

London School of Commerce
English Language and Literature, General
May 2025 - Aug 2025
Cyfrin Updraft
Smart Contracts Security; Blockchain Engineer; Smart Contracts Solidity
Jan 2024 - Jun 2025
Universidad de Antioquia
Mathematician / Mathematics
Aug 2014 - Jan 2021
Henry
Full Stack Developer; Web Applications Development
2021
Platzi
Blockchain and Cryptocurrency School
2021 - 2022

Certification

Basic JavaScript
Intermediate Object-Oriented Programming in JavaScript
Basic Python
Git and GitHub 100% Practical
TypeScript from 0 to 100

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