Sebastian Castellanos

I’m a final-semester Systems Engineering student, and I work as a Full Stack Developer Jr. I’m proactive and passionate about web development, software architecture, and system design, and I enjoy turning requirements into working end-to-end solutions.

In real work environments, I delivered full features by collaborating with teams to expand a company website, integrate new payment technologies across channels, and apply e-commerce strategies that improved online sales. I take ownership of outcomes, and I’m comfortable operating with Scrum/Agile, strong teamwork, and fast learning.

My projects reflect how I like to build: a real-time chat app using React.js with Java Spring Boot and WebSocket-based, event-driven architecture; a shopping T-shirt web app with Next.js, Node.js/Express.js, and PostgreSQL; and a traffic policy impact analysis using directed-graph modeling with A* and D* Lite plus OpenStreetMap data. I also strengthen my fundamentals through tools like a sorting algorithm compiler and my coursework in networking, UML, and data structures.