Frontend
Libraries & frameworks
Building accessible, fully typed SPAs with the tools teams rely on.
- React
- Angular
- TypeScript
- JavaScript
- SPA
- Microfrontends
- Ionic
Available for new opportunities
Javier Alonso
Frontend Engineer and IA Developer
Specialized in React and Angular — obsessed with quality, scalable architecture and solving complex problems. From monorepos and microfrontends to accessible, high-performance interfaces.
10+
Years in web development
30+
Projects delivered
4
Companies & teams
02.About me
The person behind the work
A little more about who I am, what I care about, and how I like to work.
Javier Alonso
Frontend Engineer and IA Developer
Status
Open to work
Location
Valencia, ES
I'm Javier Alonso, a frontend engineer specialized in React and Angular. I love keeping quality standards high and improving architectures — implementing design patterns, structuring monorepos and microfrontends, and solving complex problems.
Over 10 years across web, hybrid and enterprise projects, I've built SPAs, design systems and scalable apps that teams can maintain with confidence. I also care about the whole product loop — collaborating with business, product and UX to turn ideas into solid technical solutions.
React & Angular SPAs, accessible and fully typed
Monorepo (NX) and microfrontend architectures
Design systems with Storybook and MUI
AI workflows: agents, MCP and automation
03.Skills
My toolbox
The technologies and practices I use every day — grouped by the areas I focus on.
State & Data
State management & data fetching
Keeping async flows predictable with solid caching and type-safe validation.
- Zustand
- Redux
- TanStack Query
- Axios
- Zod
Quality & Design
Design systems & testing
Shipping consistent UI and confident refactors, backed by real coverage.
- Storybook
- MUI
- Vitest
- React Testing Library
- Jest
- Jasmine
- MSW
Architecture & Automation
Scalability & AI workflows
Structuring large codebases and automating work with agents and MCP.
- Monorepo (NX)
- CI/CD
- AI Agents
- MCP
- LLMs
- Jira
- Confluence
- Leading initiatives
04.Experience
Where I've worked
A track record of shipping frontend products — and improving how teams build software.
- Advanced modular React components: accessible and fully typed.
- Full async management in the frontend — fetching, caching, invalidation and concurrency with React Query.
- Frontend architecture patterns, composition and separation of responsibilities; Redux, Zustand and Zod.
- Built and maintained Storybook as the corporate design system.
- Quality testing with Vitest and React Testing Library, prioritizing coverage and continuous refactoring.
- Enterprise customer-management app on an NX monorepo, focused on scalability and maintainability.
- AI-driven automation: GitHub Copilot, LLMs and MCP flows integrated with Jira, Confluence and GitHub.
- Active part in code reviews, CI/CD and internal libraries.
- SPAs with Angular and React, focused on microfrontend architectures.
- State control with Redux, React Query and Axios.
- Unit testing with Vitest, Jest, Jasmine and MSW.
- Real-time functionality integrated via WebSockets.
- Hybrid apps with Ionic, extending reach across platforms and devices.
- Close collaboration with backend teams using Node.js for cohesive, scalable solutions.
- Led and took ownership of initiatives and developments.
- Native Android modules for WiFi/Bluetooth device registration and background voice listening against an external API.
- Secure server for Bluetooth device identification, location and tracking — designing the database, requirements and use cases.
- "Rutas escolares": school-route tracking with an Ionic + Angular frontend and a Django REST backend.
- Translation-lab management system built with .NET and C#.
- Web apps for data management: in-house PHP framework on the backend, JavaScript and jQuery on the frontend.
- WordPress corporate sites, custom themes and plugins.
- Online stores with WooCommerce.
- Responsive layouts from PSD designs and SEO optimization.
05.Education & beyond
Background
Where I learned the craft — and what keeps me sharp off the keyboard.
Educ.
Computer Engineering
Universitat de València · València
Ingeniería Informática
2019Educ.
Web Application Development
C.I.P.F.P Ausias March · València
Higher-grade training cycle (FP · DAW)
2015Extra
Football Referee
Segunda División B · FFCV
Decision-making under pressure and clear communication — skills that carry over to building software with teams.
2008 – 201506.Projects
Things I've built
A selection of projects that show how I approach problems and ship products.
Enterprise Customer Management
A large-scale customer-management app for a major telecom, built in an NX monorepo. Advanced modular React, full async state with React Query, and Storybook as the corporate design system.
ReactNX MonorepoReact QueryStorybookZod
Microfrontend Platform
SPAs with Angular and React under a microfrontend architecture. Real-time features over WebSockets, testing with Vitest, Jest, Jasmine and MSW, and hybrid mobile extensions with Ionic.
MicrofrontendsAngularReactWebSocketsIonic
School Routes Tracker
Real-time tracking of school transport routes. Ionic + Angular frontend with maps and live updates, backed by a Django REST API, with device identification and location services.
IonicAngularDjango RESTMaps
E-commerce & Corporate Web
Corporate sites, online stores and data-management apps. Custom WordPress themes and plugins, WooCommerce, and a PHP in-house framework on the backend.
WordPressWooCommercePHPMySQL