Job Opening: Senior Full Stack Developer — Fluent English We are seeking a Senior Full Stack Developer to work on an international digital transformation project at a global company that specializes in experience design, innovation, and technology solutions for major international brands. This is a 100% remote position in the EST (US) time zone, with a contractor-based contract via Deel and immediate start. **Responsibilities and Duties** Responsibilities: The professional will be responsible for developing and maintaining complete web applications — from modern and responsive interfaces to APIs, business logic, and databases. Activities include: Implementing responsive front-end interfaces using HTML5, CSS3, and JavaScript (ES6+), with experience in Vue.js or React. Creating and maintaining back-end APIs and services using .NET Core/IIS and Entity Framework. Working with relational databases (MS SQL, MySQL, or Azure SQL), query modeling and optimization. Ensure the quality, security, scalability, and performance of applications. Actively participate in architecture, code reviews, automated testing, and continuous improvement. Collaborate with designers, PMs, and developers in an agile environment, contributing to end-to-end solutions. **Requirements and Qualifications** Technical Requirements 5+ years as a Full Stack / Front-End / Back-End Developer. Strong proficiency in HTML5, CSS3, and JavaScript (ES6+). Experience with modern frameworks (preferred: Vue.js). Solid experience with .NET Core and REST APIs. Experience with relational databases. Experience with Git and version control. Fluent English (daily conversation with an international team). Availability to work in the EST time zone. Key Differentiators TypeScript Docker / Kubernetes Microservices Cloud (Azure / AWS / GCP) SSR/SSG (Nuxt.js, Blazor) Webpack / Vite CI/CD Experience with testing (Jest, Cypress, Playwright, etc.) Looking for a place where your ideas shine? With over 38 years of experience and a global presence, Stefanini transforms tomorrow — together. Here, every action counts and every idea can make a difference. Join a team that values innovation, respect, and commitment. If you are a disruptive individual, committed to continuous learning, and innovation is in your DNA, then we’re what you’re looking for. Come build a better future with us!