Hi, I'm Mario Calín Sánchez

Backend Engineer & Fullstack Developer

Backend engineer passionate about building robust, scalable systems using Java, Golang, and TypeScript. I focus on clean architecture, comprehensive testing, and applying Domain-Driven Design principles. Experienced in event-driven architectures and microservices. Additionally skilled in fullstack development with Angular and modern web technologies, with a strong foundation in best practices that ensure maintainable and reliable software solutions.

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Welcome to My Digital Space

This portfolio is more than just a showcase—it's a comprehensive view into my journey as a software engineer. Here you'll discover my technical projects, read my latest blog posts, and explore my professional background and skills.

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Projects

Curated selection of my best technical work and creative solutions

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Blog

Technical insights, learning experiences, and industry perspectives

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Resume

Professional experience, skills, and educational background

Feel free to explore and don't hesitate to get in touch if you'd like to collaborate or just have a conversation about technology.

Featured Projects

A thoughtful selection of projects that demonstrate my approach to software development and technical problem-solving. Includes both collaborative work in professional environments and personal initiatives that reflect my curiosity and dedication to the craft.

Each project represents a learning journey, an exploration of modern technologies, and a commitment to quality and elegance in code.

INDIe

Full Stack Developer

An innovative authoring tool that facilitates the creation of accessible digital resources for learning. Led by UPCT, this platform enables educators to develop inclusive educational content and has been nominated for the VII Discapnet Awards for Accessible Technologies. Over 400 open educational resources are available in the INDIeOpen repository, with more than 61,000 visits since 2021.

Java Springboot MongoDB MySQL NodeJS Angular Azure

Project description Project website Public code

Banking Transactions Challenge

Backend Developer

Technical challenge for a banking sector client focused on transaction management and financial operations. Implements domain-driven design, comprehensive unit testing, and integration testing following industry best practices. Demonstrates clean architecture, SOLID principles, robust financial data handling, and secure transaction processing patterns.

Java Spring Boot JUnit Mockito Maven OpenAPI H2 Database

GitHub

Personal Portfolio & Resume

Full Stack Developer (AI-Guided Development)

Modern, responsive portfolio website. This project showcases AI-guided development practices, combining human expertise with AI assistance to create a professional web presence. Features include automated content management, interactive design elements, and optimized user experience for both desktop and mobile devices.

Node.js Nunjucks Bootstrap 5 JavaScript CSS3 JSON Markdown AI Tools

GitHub Repository Live Website

The Most Recent Post

A Paradigm Shift: Rethinking Software Development in the Age of AI

September 13, 2026

Artificial intelligence is reshaping what it means to be a software developer. Four uncomfortable questions about work, hiring, and learning, answered.

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