Marc Guerrero
Full-Stack Developer
Valencia, Spain · Open to remote & relocation
Full-stack developer with 3 years of experience building web applications. I work with React, Next.js, Node.js and MySQL, with a focus on clean architecture and maintainable code.
Skills
Primary language for 3+ years. Used daily in both frontend (React, Next.js) and backend (Node.js). Comfortable with async patterns, closures, and modern ES2022+ features.
Adopted progressively across projects to catch bugs at compile time. Now my default for any new codebase — especially valuable in larger Next.js apps.
Main frontend framework for 3 years. Built SPAs, dashboards and component libraries. Deep understanding of hooks, context and component composition.
Used in production for a client project — full app with Server Components, API routes, auth and MySQL integration. Comfortable with the App Router and server/client boundary.
Backend runtime for REST APIs and server-side logic. Experience with Express, middleware design, JWT auth and database integration.
Relational DB of choice for most projects. Designed schemas from scratch, written complex queries, managed migrations and handled relationships across multiple tables.
Daily driver for version control. Comfortable with branching strategies, rebasing, resolving conflicts and collaborating via GitHub pull requests.
Relational database used in production. Comfortable with schema design, migrations and query optimisation in a PostgreSQL environment.
Open-source headless ecommerce framework. Using it in production — managing product catalogue, carts, checkout flows and a custom backoffice backed by PostgreSQL.
Load testing tool used before production launch — simulated real user traffic to find capacity limits, identify bottlenecks and optimise slow pages and processes.
Deployment platform for production apps. Managing environment variables, services and deploy pipelines for the MyUrbanScoot ecommerce stack.
Integrated AI tools into daily development workflow — using Claude for code review, architecture decisions and debugging. Comfortable working with and prompting LLMs effectively.
Projects
DJ Booking Platform
PrivateFull-stack web app for a professional DJ — public-facing site with booking requests and a private backoffice for the client to manage gigs, availability and content autonomously.
Experience
Building a full-stack ecommerce platform using Medusa — product catalogue, cart, checkout flows and a custom backoffice. PostgreSQL backend with custom business logic on top of Medusa's core modules. Ran load tests with k6 before launch to identify bottlenecks and validate the platform under real traffic conditions.
Developed features for a B2B video streaming platform serving media clients across Europe. Built customisable embeddable players, geo-restriction controls and analytics dashboards. Integrated an AI transcription pipeline with a human review interface for video captions.
Designed and built web applications for clients end-to-end, from database schema to deployed UI. Projects include a booking platform with a custom backoffice.
Built and maintained a B2B video hosting and live streaming platform. Developed embeddable players with per-client customisation, region-based access control and a real-time chat service for live streams.