Sebastian Echeverri MejiaFull Stack Engineer
I build production-ready SaaS platforms and scalable web applications focused on analytics, performance, and real-world business operations. From high-performance frontends to secure backend architectures — I create software that scales and drives measurable business impact.
Engineering That Delivers
I'm a Full Stack Engineer focused on building production-ready SaaS platforms, analytics systems, and scalable business applications.
I specialize in designing clean architectures, building secure backend systems, and translating complex business operations into scalable software. Throughout my career, I've developed systems focused on analytics, operational efficiency, and real-world usability — improving workflows, reducing manual processes, and delivering measurable impact.
Outside of engineering, I'm passionate about sports, especially tennis — which has shaped my mindset around discipline, consistency, and continuous improvement. I bring that same energy into my work: always learning, always iterating, and always looking for better ways to build and collaborate.
Performance First
High-performance applications with strong Lighthouse scores and optimized user experience across production systems.
Full Stack
Modern full-stack systems with React, Next.js, Node.js, PostgreSQL, .NET, and scalable cloud architectures.
Product Mindset
I build with the end user and business goals in mind, not just the code — focusing on impact and usability.
Engineering Impact
Focused on building scalable SaaS systems that improve operations, simplify workflows, and deliver measurable business impact.
Technologies I Work With
Battle-tested tools I use to build production systems.
Frontend
Backend
Databases
DevOps & Tools
What I've Built
From full-stack SaaS platforms to AI-powered interfaces — built for scalability and performance.
Production-grade SaaS application
Cattle farm operations were being managed through notebooks and spreadsheets, making financial tracking, livestock monitoring, and operational reporting difficult to scale.
Key Features
- ▸ Livestock lifecycle management
- ▸ Financial reporting & analytics
- ▸ Multi-tenant farm isolation
- ▸ Role-based admin system
Engineering
- ▸ Executive dashboard with KPIs & charts
- ▸ Secure authentication & email workflows
- ▸ Server Actions architecture
Full-stack MERN application
Teams needed a powerful way to manage projects and tasks with real-time collaboration, role-based access, and a scalable backend.
Key Features
- ▸ Project & task management (Trello-style workflow)
- ▸ Role-based access (owners & collaborators)
- ▸ Drag & drop task organization (DnD Kit)
- ▸ Authentication with JWT & protected routes
Engineering
- ▸ REST API with Express & MongoDB (Mongoose)
- ▸ Server state management with React Query
- ▸ Schema validation with Valibot (type-safe API)
- ▸ Modular backend (controllers, services, middleware)
AI-powered frontend application
Users needed a fast way to discover drinks and generate custom recipes without manually browsing multiple sources.
Key Features
- ▸ Search drinks via TheCocktailDB API
- ▸ AI-powered recipe generation (OpenRouter)
- ▸ Favorites persistence with localStorage
- ▸ Recipe modal with Headless UI
Engineering
- ▸ Global state management with Zustand (slice pattern)
- ▸ Schema validation with Zod for type-safe APIs
- ▸ Client-side routing with React Router
- ▸ Reusable and modular component structure
- ▸ AI integration via OpenRouter with dynamic prompt handling
State-driven frontend application
Users needed a simple way to track expenses, manage budgets, and visualize spending without relying on complex tools.
Key Features
- ▸ Budget tracking with visual progress (donut chart)
- ▸ Add, edit, and delete expenses
- ▸ Category-based expense organization
- ▸ Gesture-based actions (swipe to edit/delete)
Engineering
- ▸ State management with Context API and useReducer
- ▸ Persistent storage with localStorage
- ▸ Component-driven architecture with reusable logic
- ▸ Interactive UI patterns (modals, gestures, charts)
- ▸ Reducer-based state transitions for predictable updates
Where I've Shipped
Full-Stack Developer
Fuel Web Marketing · St. Petersburg, FL
- ▸ Built and deployed 7 high-performance React applications with Lighthouse scores of 85+ and perfect scores in SEO, accessibility, and best practices.
- ▸ Designed a reusable component architecture that reduced delivery time by ~20% across projects.
- ▸ Integrated AI-powered chat solutions using LLMs, increasing user engagement and helping attract new clients.
- ▸ Developed secure REST APIs with Node.js, Express and JWT for dynamic content and form workflows.
Full-Stack Developer
Binapps S.A.S · Manizales, Colombia
- ▸ Developed scalable features for a multi-tenant electronic billing SaaS platform used by enterprise clients.
- ▸ Automated client onboarding processes, reducing activation time by 50%.
- ▸ Built and optimized backend services with .NET and SQL Server, improving system performance and reliability.
- ▸ Collaborated across teams to deliver new ERP features and integrations.
Full-Stack Developer
Centro Galerías Plaza de Mercado · Manizales, Colombia
- ▸ Migrated financial operations from Excel into a centralized web application.Migrated financial operations from Excel into a centralized web application.
- ▸ Implemented role-based authentication and real-time notifications using Socket.io.
- ▸ Built full-stack features to improve internal workflows and communication efficiency.
B.S. Software Engineering
Universidad Autónoma de Manizales · 2019 – 2025
Let's Build Something
I'm open to full-time roles, freelance work, and interesting collaborations. If you're building something meaningful or need help scaling your product — let's talk.