Experience
Frontend Developer (Angular & RxJS)
Metrica Sports | May 2025 - Present | Full Time
- Developed high-performance, reactive interfaces for a professional sports video analysis platform using Angular. - Built and took ownership of features from scratch to MVP and full production deployment in a fast-paced startup environment. - Managed complex state and real-time data flows using RxJS. - Delivered cross-platform applications using Angular, Electron, and Ionic - Collaborated closely with product and design teams to improve UX/UI and performance
Lead Developer (Python & React & FastAPI & AWS)
Spotify Electron | May 2023 - Present | Freelance
- Led a 25+ contributor open-source project, managing workflows, PRs, and releases. - Designed a distributed music streaming architecture using AWS (S3, CloudFront, Lambda). - Built REST APIs with FastAPI, MongoDB, and JWT authentication. - Developed a cross-platform desktop app using React, TypeScript, and Electron. - Delivered a scalable system replicating core Spotify features with additional user-driven functionality. - Implemented CI/CD pipelines (GitHub Actions) and Dockerized environments.
Founder and Lead Developer (Node.js, TypeScript)
AdventJS CLI | October 2025 - Present | Freelance
The all-in-one command-line tool for AdventJS challenges. Save hours of repetitive setup with a single command and focus on solving, not configuring. - Generates a TypeScript solution template, problem docs, and Jest tests. - Fully preconfigured environment with debugging, linting, formatting, and CI. - Consistent workflow every year, built from personal experience.
Full-Stack Developer (Python & Angular & FastAPI)
Bionet | October 2023 - Jul 2025 | Full Time
- Designed and implemented a microservices architecture using Python (FastAPI) and Redis for real-time communication between hardware and software systems. - Developed full-stack solutions for embedded bioreactor systems, integrating frontend (Angular), backend (Python - FastAPI), and low-level hardware communication (OPC UA). - Acted as software lead for multiple devices, coordinating with electronics teams and stakeholders. - Led the migration from Angular 12 to Angular 19, improving maintainability and performance. - Contribute to architecture planning and decision-making for system design. - Implemented backend testing (pytest) and frontend testing (Karma, Jasmine).
Full-Stack Developer (PHP & JavaScript)
Byprox | Jan 2022 - Jun 2022 | Internship
- Developed a full-stack travel application using PHP, JavaScript, and MySQL - Designed hierarchical navigation across locations and points of interest. - Built responsive UI with HTML, CSS, and JavaScript.
Projects
AdventJS 2024
My solutions to the AdventJS 2024 challenge AdventJS is an annual event that helps developers improve their coding skills with 25 progressively harder challenges leading up to Christmas. Each day, a new challenge is released, and participants are encouraged to solve it and share their solutions.
Certifications
![[In progress] NestJS Microservices — Build & Deploy a Scalable Backend](/Portfolio/_astro/udemy.DP2B5Kpn_24nMBD.webp)
[In progress] NestJS Microservices — Build & Deploy a Scalable Backend
Agile Estimation with Planning Poker
Product Owner Course in Practice
Advanced Scrum Course
Design and Use a Kanban Board
Technical Scrum Course
Scrum: Managing Teams with Scrum
Managing Agile Sprints with Scrum
Testing with Vitest
Education
Computer Science Degree
University of Murcia | 2019 - 2023
- Grade: 7.5/10 (GPA 3.3/4.0) - Software Engineering Specialization - Software Architecture with Honors
Languages
Personal
- 🇪🇸 Spanish: Native - 🇬🇧 English: C1 (Advanced)
About Me
Hi I'm Antonio! 👋
My name is Antonio Martinez, and I'm a Senior Full-Stack Developer with +4 years of real-world experience building integrated frontend-backend solutions. My main tech stack includes Python, FastAPI, Angular, React, and Node.js. I have worked in fast-paced international startups, taking ownership of product features end-to-end and collaborating closely with teams using my advanced English skills. I am fluent in both English and Spanish. Music is a big passion of mine—I dedicated three years to Spotify Electron, an open-source music streaming app I built from scratch. The project replicates the Spotify UI, adds new features such as allowing users to upload songs, and provides a platform for discovering emerging artists. I led the project and coordinated over 30 contributors from around the world, gaining experience in open-source leadership, collaboration, and community-driven development. I am a daily Linux user and enjoy understanding systems at a deeper level. I like experimenting with tools, optimizing workflows, and staying up to date with modern technologies and industry trends. I strongly believe in continuous improvement and strive to become at least 1% better every day, both technically and professionally. Outside of work, I enjoy sports and music. I regularly practice trail running, cycling, gym training, and padel. I hold a degree in Computer Science from the University of Murcia, where I specialized in Software Engineering.
Contact
antoniomartinezfernandez17@gmail.com
linkedin.com/in/antonio-martinez-fernandez-dev
Github
github.com/AntonioMrtz