Available for new opportunities
Hello, I'm Guillermo
I build impactful web experiences by combining beautiful interfaces with robust architectures. I'm passionate about clean code and creative solutions.
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TypeScriptC#JavaSQLSolidityJavaScriptReactHTML5CSS3Tailwind CSSNext.jsCI/CDGitGitHubAPI IntegrationDockerMongoDBSQL ServerMySQLSupabaseFirebasePostgreSQLNode.js.NETExpress.jsREST APINestJSTypeScriptC#JavaSQLSolidityJavaScriptReactHTML5CSS3Tailwind CSSNext.jsCI/CDGitGitHubAPI IntegrationDockerMongoDBSQL ServerMySQLSupabaseFirebasePostgreSQLNode.js.NETExpress.jsREST APINestJS
// 01. ABOUT ME
Get to Know Me Better
Passionate developer creating extraordinary digital experiences
👨💻
⚡ React Expert
🔗 Open Source
🧩
Problem Solver
Logical & Creative
🚀
Tech Enthusiast
Latest technologies
📚
Continuous Learner
Growth mindset
🤝
Team Player
Collaboration first
A story of code and creativity
I am a Full Stack developer passionate about building beautiful interfaces and robust backends. With an eye for design and a love for clean code, I turn complex problems into elegant solutions.
My journey involves constant learning and pushing the boundaries of modern web technology. When I'm not programming, I'm exploring trends in UI/UX, contributing to open source, or just relaxing.
Technical Skills
TypeScriptC#JavaSQLSolidityJavaScriptReactHTML5CSS3Tailwind CSSNext.jsCI/CDGitGitHubAPI IntegrationDockerMongoDBSQL ServerMySQLSupabaseFirebasePostgreSQLNode.js.NETExpress.jsREST APINestJS
// 02. PROJECTS
Work Highlight
Collection of high-performance web applications built with modern technologies
Vaén
Developing a full-stack e-commerce platform that provides product browsing, advanced filtering by price, size, and categories, and a modern responsive...
NestJSNext.jsTypeScriptPrismaSupabaseStripeClerkTailwind CSSshadcn/ui
CVision
Developing an AI-powered platform that analyzes a candidate’s CV against job descriptions to evaluate alignment and provide actionable improvement fee...
Next.jsTypeScriptPrismaSupabaseClerkZodVAPITailwind CSS
// 03. EXPERIENCE
Professional Background
My journey through the world of software development
Ene 2025 – Oct 2025
Open-Source Software Contributor
OnlyDust·Remote
- ▹Contributed to Web3 open-source platforms by implementing new features and fixing critical bugs across multiple repositories.
- ▹Collaborated in full-stack development using TypeScript, Next.js, and NestJS, improving system performance and maintainability.
- ▹Refactored legacy code and applied clean architecture principles to improve scalability and readability.
- ▹Participated in pull request reviews and code integration, maintaining high quality and coding standards.
- ▹Worked in distributed international teams, improving collaboration and communication in remote environments.
Jul 2024 – Nov 2024
Full-Stack Developer
Asociación Voluntarios de Corazón·Montes de Oca, Costa Rica
- ▹Designed and developed a full-stack web platform using the MERN stack (MongoDB, Express.js, React, Node.js) to manage pet adoption, reservations, and shelter operations.
- ▹Built and maintained a RESTful API using Node.js and Express.js, enabling secure and scalable client-server communication.
- ▹Implemented JWT-based authentication and authorization, ensuring secure user access and session management.
- ▹Developed an admin dashboard for managing users, pets, and reservations with role-based access control.
- ▹Integrated PayPal payment processing, automated email notifications, and WhatsApp messaging for real-time system events.
- ▹Optimized database queries and backend logic, improving performance and system reliability
Sep 2023 – Jul 2024
Full-Stack Developer
Unicoop R.L.·San Pedro, Costa Rica
- ▹Developed a cooperative crowdfunding and management system handling users, financial transactions, and member data.
- ▹Built backend services using .NET Core and ASP.NET Web API, implementing scalable and maintainable architecture.
- ▹Implemented secure authentication and role-based access control (RBAC) for financial and administrative operations.
- ▹Integrated Dapper ORM for high-performance data access and execution of SQL Server stored procedures.
- ▹Designed and optimized relational database structures using Microsoft SQL Server, improving data integrity and query performance.
- ▹Led development lifecycle including architecture design, development, testing, and deployment.
Nov 2022 – Jun 2023
IT Support
La Catalina R.L.·San Pedro, Costa Rica
- ▹Co-developed a secure voting and revenue tracking system using .NET Core, improving transparency in internal operations.
- ▹Participated in system design, testing, and implementation aligned with business and technical requirements.
- ▹Provided IT support and troubleshooting, reducing downtime by approximately 40% during system rollout.
- ▹Helped digitize internal decision-making processes, improving efficiency and data accuracy
Education
🎓
Ethereum Developer Pack
CENFOTEC University
May 2025 – Sep 2025San José, Costa Rica
🎓
Bachelor’s Degree in Computer Systems Engineering
Fidelitas University
Ene 2022 – Mar 2025San José, Costa Rica
// 04. CONTACT
Let's Talk
Have a project in mind? I'd love to hear about it!
Available for opportunities
Location
San José, Costa Rica