Willian Peres de Oliveira

At Cayena, on the frontend I delivered improvements across the buyer portal — product listing, checkout, scheduling, and order creation — and helped design and build a high-value sales platform for enterprise transactions, including accounts payable, invoice handling, and financial breakdowns. On the backend, collaborated on Java services implementing order lifecycle, finance workflows, and logistics updates. Refactored parts of the codebase and incorporated AI-assisted development tools.

Allocated at Nutrien Ag Solutions, the world's largest agricultural inputs provider. Contributed to a credit request platform used by large-scale farmers, working on both the credit application flow and a system aggregating government and third-party data to display credit scores and financial insights. Delivered React Native features within a micro-frontend architecture and implemented Node.js and GraphQL backend enhancements. Also supported junior developers and helped maintain engineering standards.

Led the end-to-end development and App Store/Play Store release of a React Native mobile app, achieving 10,000+ downloads and a 4.9-star rating. Built core features including checkout, payments, scheduling, push notifications, and deep linking. Designed and implemented the company's digital wallet system, covering fund creation, refunds, balance management, and payment processing. Also contributed to backend microservices for orders and payments using NestJS, RabbitMQ, and PostgreSQL.