VTEX Flutter Fullstack Engineer

UST is searching for a Fullstack Software Developer who will develop and maintain custom apps in VTEX IO and Store Themes; configure Checkout, Promotions, Master Data, OMS, Catalog, and Payments.

The opportunity:

• Build high-performing storefronts with React/TypeScript, optimizing Core Web Vitals, SSR, and caching. Integrate VTEX APIs (REST/GraphQL) and FastStore (preferred) using a headless commerce approach.

• Backend & Architecture: Design and implement microservices and REST/GraphQL APIs (Node.js/TypeScript), with ORM and relational databases (e.g., PostgreSQL/MySQL).

• Ensure security (OAuth2/JWT, rate limiting, input validation, secrets management) and observability (logs, metrics, traces). Document with OpenAPI/Swagger and maintain high quality with unit/integration testing (Jest; Cypress for end-to-end).

• Mobile - Flutter Design and develop Flutter apps with Clean Architecture, state management (BLoC/Cubit/Riverpod), modularization, and performance best practices (profiling, lazy loading, custom painters where applicable).

• Integrate mobile payment methods, push notifications, WebSockets/real-time, and Firebase (Auth, Firestore, Messaging) where applicable.

• Automate mobile CI/CD, code signing, and publishing/version management (enterprise or stores). Payments Integration with PSPs/gateways, tokenization/vault, 3DS, reconciliation, and reversal/retry flows.

• PCI compliance and controls (within the scope of the role), fraud prevention, and integration with anti-fraud/scoring systems. Design for high availability, resilience, and fault tolerance in critical payment flows.

• Collaboration & Leadership: Gathering requirements from business/finance/compliance and technical stakeholders. Mentoring mid/junior developers; end-to-end ownership from design to operation. Creating clear and maintainable technical documentation.

This position description identifies the responsibilities and tasks typically associated with the performance of the position. Other relevant essential functions may be required.

Do you have experience in WebSocket?, * VTEX Ecosystem: Proven experience with VTEX: store configuration and customization, VTEX IO, custom app development, Checkout, Master Data, OMS, Catalog, and promotions. Integration with VTEX APIs (REST/GraphQL) and experience with Site Editor/CMS.

• Web Frontend: React + TypeScript + JavaScript (ES6+). HTML5/CSS3 (advanced proficiency), responsive/Mobile-First. Design patterns and accessibility; optimization of Core Web Vitals and SSR/caching.

• Backend: Node.js + TypeScript; design and development of REST/GraphQL APIs. ORM (e.g., TypeORM/Prisma/Sequelize) and relational databases (PostgreSQL/MySQL). Microservices, Clean Architecture, and SOLID principles.

• Security: OAuth2/JWT, rate limiting, validation, basic auditing. Swagger/OpenAPI for documentation.

• Quality & DevX: Unit testing (Jest) and end-to-end testing (Cypress preferred). Git (branching/PR/code review), CI/CD (GitHub Actions/Bitbucket Pipelines).

• Observability: structured logging, metrics, and traces (hands-on experience preferred). Mobile - Flutter Intermediate to advanced Flutter development: Clean Architecture, BLoC/Cubit/Riverpod, modularization, and performance best practices. Integration with payment platforms and Firebase (Auth/Firestore/Messaging) where applicable. Build automation and code signing (CI/CD mobile).

• Payments (domain) Extensive experience in e-commerce payments: payment orchestration, tokenization, 3DS, reconciliation, fraud prevention, retries, and error handling. Knowledge of PCI (within the developer's scope), security best practices, and payment compliance. Desired Skills FastStore in VTEX and advanced caching strategies.

• Docker and Kubernetes; cloud experience (AWS/GCP/Azure) for microservices. React Native (plus) and native iOS/Android modules. Complex integrations with ERP/OMS/CRM and messaging/streaming (pub/sub, events).

• Experience with advanced rate limiting, retries with backoff, and circuit breakers. Infra as Code (Terraform), feature flags, and toggling. Experience with high availability and SRE (basic SLO/SLI/SLAs)., software engineering,flutter development,payment domain,integration testing,relational database

Pulled from the full job description

• Dental insurance
• Life insurance
• Disability insurance
• Paid holidays, Employees receive eleven (11) paid holidays, two (2) weeks of paid vacation per year, and are eligible for health, dental, disability and life insurance.

Born digital, UST transforms lives through the power of technology. We walk alongside our clients and partners, embedding innovation and agility into everything they do. We help them create transformative experiences and human-centered solutions for a better world. UST is a mission-driven group of 29,000+ practical problem solvers and creative thinkers in more than 30 countries. Our entrepreneurial teams are empowered to innovate, act nimbly, and create a lasting and sustainable impact for our clients, their customers, and the communities in which we live. With us, you'll create a boundless impact that transforms your career-and the lives of people across the world., We proudly embrace the values that have shaped UST since day one. We build our culture of Humility, Humanity, and Integrity. These values inspire us to nurture a people-first, human centric culture that fosters diversity, prioritizes sustainable solutions, and keeps our people and clients at the forefront of all decisions., UST is a global digital transformation solutions provider. For more than 20 years, UST has worked side by side with the world's best companies to make a real impact through transformation. Powered by technology, inspired by people and led by purpose, UST partners with their clients from design to operation. With deep domain expertise and a future-proof philosophy, UST embeds innovation and agility into their clients' organizations. With over 30,000 employees in 30 countries, UST builds for boundless impact-touching billions of lives in the process.