Product-focused Full-Stack Engineer with 1.5+ years of professional experience building and shipping production SaaS products at a Swiss startup. Strong in React, Next.js, TypeScript, APIs, and PostgreSQL, with hands-on ownership across frontend, backend, AI integrations, and complex data workflows. MSc in Financial Technologies (High Honors) and BSc in Physics, with experience turning ambiguous product and customer needs into end-to-end technical solutions spanning UI/UX, database workflows, permissions/validations, and LLM-powered data access.…

Sergio Barbero García

Product-focused Full-Stack Engineer with 1.5+ years of professional experience building and shipping production SaaS products at a Swiss startup. Strong in React, Next.js, TypeScript, APIs, and PostgreSQL, with hands-on ownership across frontend, backend, AI integrations, and complex data workflows. MSc in Financial Technologies (High Honors) and BSc in Physics, with experience turning ambiguous product and customer needs into end-to-end technical solutions spanning UI/UX, database workflows, permissions/validations, and LLM-powered data access.…

Available to hire

Product-focused Full-Stack Engineer with 1.5+ years of professional experience building and shipping production SaaS products at a Swiss startup. Strong in React, Next.js, TypeScript, APIs, and PostgreSQL, with hands-on ownership across frontend, backend, AI integrations, and complex data workflows.

MSc in Financial Technologies (High Honors) and BSc in Physics, with experience turning ambiguous product and customer needs into end-to-end technical solutions spanning UI/UX, database workflows, permissions/validations, and LLM-powered data access.

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Skills

Experience Level

React JS
Expert
TypeScript
Expert
Tailwind
Expert
API
Expert
PostgreSQL
Expert
SEO
Expert
SaaS
Expert
AI Chatbot
Expert
Large Language Model
Expert
n8n
Expert
Prompt Engineering
Intermediate
Docker
Intermediate
Data Visualization
Beginner
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Language

Spanish; Castilian
Fluent
English
Advanced
German
Beginner
French
Beginner

Work Experience

Freelance Frontend Creative Web Developer
January 1, 2026 - Present
Independent frontend developer delivering production websites (from Figma/concepts/client requirements). Owned responsive UI, interactions, SEO/GEO, performance, deployment, and maintenance. Collaborated with boutique agencies and shipped projects from requirements and prospecting through production.
Frontend Engineer at Neomir GmbH
November 1, 2025 - August 1, 2026
Led an end-to-end refactor and continuous development of Neomir.com. Improved architecture, responsiveness, SEO/GEO, UX, and performance to reach a 100/100 Google PageSpeed score. Mentored two junior developers and contributed to technical decisions, implementation reviews, and development workflows.
Full Stack Engineer at Neomir GmbH
May 1, 2025 - August 1, 2026
Built and shipped production B2B features end-to-end across React/Next.js interfaces, API logic, PostgreSQL views, permissions/validations, and enterprise data workflows. Owned features from ambiguous customer/product problems through technical implementation across frontend, backend, database, and AI layers. Delivered onboarding, invitations, dashboards, asynchronous states, polling, error handling, data access, and enterprise workflows in collaboration with product stakeholders and customers.
Founder / Full-Stack & AI Engineer at SmartHotels
January 1, 2025 - May 1, 2025
Founded and built an AI-assisted hotel email automation platform piloted with two 4- and 5-star hotels. Owned APIs, data models, asynchronous workflows, and LLM integrations; built RAG workflows retrieving relevant context from ~60 pages of hotel information to support customer conversations. Achieved ~90% automation and ~400% ROI across two pilot clients.
AI & ML Engineer Intern at Neomir GmbH
January 1, 2025 - May 1, 2025
Designed and developed Neomir AI to enable plain-language insights from structured SAP and Salesforce data. Built AI-driven data access workflows combining schema context, retrieval, structured enterprise data, LLMs, RAG, and NL2SQL to support query understanding and data grounding.

Education

MSc in Financial Technologies (FinTech) at Carlos III University of Madrid
January 1, 2024 - January 1, 2025
BSc in Physics at University of Salamanca
January 1, 2020 - January 1, 2024

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Financial Services, Professional Services, Travel & Hospitality, Computers & Electronics