Cosme Valera Reales

Software Developer

About

Four years building web applications. Right now I work at GMV on Galileo, Europe's satellite navigation system, where most of my day is React and TypeScript and the rest is Node, Java and getting things deployed to Kubernetes.

AI is part of how I work every day. I've built projects with Claude Code, Codex and Cursor, and I go well past the chat box into agents, skills, rules and MCP servers. I follow the space closely and keep whatever survives contact with a real project, which is also how RabbitHole got built.

That raised the bar for the basics instead of lowering it. A lot of what I ship now starts as agent output, so reviews, tests and refactoring are what keep it honest, and a clear codebase is the one an agent gets right on the first try. The standard does not change because the author is not human.

Experience

Mid-Level Frontend Developer

GMV Madrid, Spain

10/2023 – Present

Contributed to the development and delivery of web applications to meet ESA's needs in the Galileo project. Galileo is Europe's global satellite navigation system.

Developed and maintained 5+ frontend applications using React, TypeScript and CSS, improving usability and consistency across Galileo applications.
Built and deployed containerized applications across 2 Kubernetes environments using Docker, Helm and Kustomize, reducing manual deployment steps by moving configuration values into Helm.
Automated monthly deployments of applications across environments using Jenkins.
Contributed to backend services using Node and Java (Spring).
Worked with ESA engineers to clarify requirements, gather feedback and translate operational needs into user stories and features.
Improved maintainability through code reviews, pair programming, refactoring and clean code principles.
Engaged in Agile events (stand-ups, planning, retrospectives) and defined project needs and user stories.

React
TypeScript
CSS
Node
PostgreSQL
Docker
Kubernetes
Helm
AWS
Jenkins
Git
Scrum

Junior Full Stack Developer

Seanchas Research Cork, Ireland

04/2023 – 07/2023

Very enriching Erasmus+ experience working full-time in English in Ireland.

Developed and updated 2 web applications: one full-stack application using Angular, TypeScript, CSS, Java and MySQL, and one WordPress-based website.
Used Git and GitHub Actions to support version control and deployment workflows.

Angular
TypeScript
CSS
Java
MySQL
WordPress
Git
GitHub Actions

Capgemini

Murcia, Spain 04/2022 – 04/2023

Junior Full Stack Developer

07/2022 – 04/2023

Developed web applications for ADIF railway infrastructure systems, supporting services related to Renfe trains and national rail operations, using Angular, TypeScript, CSS and Java (Spring).
Built responsive interfaces from Figma designs and client requirements, aligning frontend implementation with business and usability needs.

Full Stack Developer Intern

04/2022 – 07/2022

Started with Angular and Java. Three months as an intern, then hired.

Angular
TypeScript
CSS
Java (Spring)
PostgreSQL
Git
Figma
Scrum

Projects

RabbitHole Flagship project

2023 – Present

Turns one prompt into a multi-page AI guide, explained through what you already know. Start anywhere, go as deep as you want.

6+ months of focused work spread across the last 3 years

Generates multi-page guides with lessons and exercises from a single prompt, anchored to the background knowledge the reader picks.
Turns any guide into quizzes, flashcards or a podcast recap in one click, with an AI chat and web search to expand it on demand.
Runs on the AI you choose: hosted, your own API key, or a local model on your machine.
Turborepo monorepo with serverless API routes, covered by Vitest and Playwright.