Loris Léonard

Artrade is a French platform for real-world assets (RWA). It allows users to purchase luxury goods through Solana in a transparent and deterministic way. The platform originally offered discounted items through raffles, and now includes auctions and booster packs. - Built and maintained the backend in Deno using Hono (async REST routes, database, business logic) with transparency and consistent execution of features like raffle winners, auctions, booster packs, and buyback. - Built scheduled cron tasks for notification system, checking balances, ending raffles, and triggering automated actions on user funds and RWA services. - Managed backend interactions with Solana to send funds to users, ensuring correct amounts, no duplication and reliable execution. - Added real-time features with Socket.IO, letting users see live updates and auction activity instantly. - Improved reliability with centralized error handling, Sentry logging, separation of layers, and ensured endpoints followed backend best practices with proper validation, typing and consistent database state.

I provided DeFi data to the most popular Japanese crypto tax solution and built a new portfolio tool to strengthen Pafin’s DeFi offering. A key part of the work was decoding dapp smart contracts across several blockchains to retrieve where assets were stored (liquidity, staking, rewards) and to perform advanced transaction decoding for tax purposes. This allowed us to calculate taxes correctly and give users a clear picture of their holdings. - Engineered scalable microservices in Python with PostgreSQL, Twirp RPC (Protobuf), and JSON-RPC blockchain integrations, using async execution with retries, plus caching for real-time data. - Automated in Python the decoding of millions of On-chain transactions across Ethereum, Polygon, Optimism, and Arbitrum, extracting actionable fields for analytics and tax services. - Integrated web3.py library to investigate how protocols store assets in Solidity smart contracts in order to analyze DeFi positions (liquidity, staking, swaps) across Uniswap, OpenSea, Aave, Curve, and Velodrome. - Built the frontend from Figma designs with Next.js and TypeScript, integrating APIs and optimizing load time and performance. - Performed daily code reviews, testing and refactoring to improve code quality, consistency, and maintainability across backend and frontend projects.