Fullstack Software Developer (VTEX, React, Node.js, Flutter)

About the role

UST is looking for a Fullstack Software Developer to design, build, and maintain custom e‑commerce applications on the VTEX platform and mobile solutions with Flutter. You will work across the stack, from high‑performing React storefronts to Node.js micro‑services and payment integrations.

Key responsibilities

• Develop and customize VTEX IO store themes, checkout, promotions, master data, OMS, catalog and payment flows.
• Build responsive React/TypeScript storefronts, optimise Core Web Vitals, implement SSR and caching.
• Design and implement Node.js/TypeScript micro‑services and REST/GraphQL APIs with PostgreSQL or MySQL.
• Create and maintain mobile applications using Flutter with Clean Architecture, BLoC/Cubit/Riverpod state management and Firebase services.
• Integrate payment service providers, ensure PCI compliance, fraud prevention and high‑availability payment flows.
• Write OpenAPI/Swagger documentation, unit and integration tests (Jest, Cypress) and ensure observability through logs, metrics and traces.
• Mentor junior developers, gather requirements from business, finance and compliance stakeholders, and produce clear technical documentation.

Required profile

• Proven experience with the VTEX ecosystem, including store configuration, custom app development and checkout integration.
• Strong background in React, TypeScript, Node.js and relational databases.
• Hands‑on experience building Flutter applications with modern state‑management patterns.
• Understanding of security best practices (OAuth2, JWT, rate limiting) and payment compliance (PCI, 3DS).
• Ability to work autonomously, lead technical discussions and guide less‑experienced team members.

Required skills

• VTEX IO, VTEX APIs (REST, GraphQL), FastStore
• React, TypeScript, Server‑Side Rendering, Core Web Vitals
• Node.js, TypeScript, micro‑services, ORM
• PostgreSQL, MySQL
• OAuth2, JWT, input validation, secrets management
• OpenAPI/Swagger, Jest, Cypress
• Flutter, Clean Architecture, BLoC, Cubit, Riverpod
• Firebase (Auth, Firestore, Messaging)
• CI/CD pipelines, code signing, mobile publishing
• Payment gateway integration, tokenization, 3DS, PCI compliance