julian90

Worked on the development and maintenance of fintech and crypto-related platform features, focusing on API integrations, payment infrastructure, and scalable backend services. Contributed to: • Third-party API integrations • Binance-related integrations • Payment processing systems • Backend services and microservices architecture • Frontend and backend feature development • Unit and integration testing • Platform stability and performance improvements Tech stack: Ruby on Rails, React, React Native, Blockchain, PostgreSQL, Node.js, JavaScript, TypeScript.

Designed and developed multiple blockchain and Web3 applications focused on DeFi infrastructure, NFTs, tokenized platforms, governance systems, healthcare services, payment integrations, and decentralized applications. Worked across smart contract architecture, security-focused development, frontend applications, backend integrations, wallet connectivity, and blockchain infrastructure, contributing to the full lifecycle of decentralized products. Main Contributions • Developed smart contracts using Solidity and OpenZeppelin standards • Built ERC20, ERC721, and subscription-based blockchain systems • Implemented wallet integrations with MetaMask and Web3 providers • Developed decentralized applications using React, Ethers.js, wagmi, and modern Web3 tooling • Built integrations using JSON-RPC communication flows and blockchain SDKs • Participated in frontend, backend, and smart contract architecture decisions • Implemented security-focused smart contract development practices • Performed unit testing, fuzz testing, invariant testing, and smart contract validation workflows • Utilized security analysis tools such as Slither and Aderyn for static analysis and vulnerability detection • Worked with decentralized storage solutions and blockchain-based authentication systems Technologies Solidity, Foundry, Hardhat, React.js, TypeScript, Ethers.js, wagmi, viem, OpenZeppelin, Node.js, Express.js, PostgreSQL, MetaMask, IPFS, Slither, Aderyn, blockchain SDKs.

Developed a blockchain-based exchange platform focused on asset interoperability, fiat and crypto transactions, and real-time blockchain interactions using Stellar network infrastructure. Built and integrated: • Blockchain transaction flows using Stellar SDK • Asset exchange functionalities • Real-time communication with WebSocket.IO • Frontend and backend integrations • Secure transaction handling • Scalable backend services The platform enabled users to exchange fiat and crypto assets through a simple and secure blockchain-powered interface. Tech stack: JavaScript, React.js, Node.js, Express.js, Supabase, WebSocket.IO, Stellar SDK.

financial markets analyst, including forex, crypto assets, everything related to CFDs on stocks and stock markets in general.