About - Karelys Denis

Full-Stack Developer & UX Specialist

Over 10 years and 20+ production projects in healthcare, e-commerce, legal, and cultural sectors. I build with React and Node.js for custom platforms, and WordPress for content-driven sites, always combining development with user-centered design. My approach is product-first: understand the business goal, validate with real users, and deliver software that actually solves the problem.

Location: Chile / Spain / France

Languages: Spanish (Native), English (B2), Portuguese (B1)

What I Do

I build complete web applications, from frontend interfaces to backend APIs and infrastructure. Every project starts with the business goal, not just the technical requirements. I design with real users in mind, prototype fast, and iterate based on data. I integrate well into existing teams and adapt quickly to their workflows. You get direct communication, measurable progress, and working software.

Who I Work With

Startups building their MVP or scaling their product. Companies needing dashboards, internal tools, or web platforms. Businesses looking to improve their digital presence and conversion. Teams that need someone who bridges product thinking and technical execution.

Professional Experience

Applications Lead & Co-founder - Applauss

2025 - Present | Spain

Leading development of user-facing applications and interaction flows for AI-based event recommendation platform. Translating research hypotheses into testable interfaces for intent capture and recommendation display. Designing dashboards for user behavior monitoring and establishing user testing protocols to validate UX against research outcomes.

Full-Stack Developer & Project Manager - Freelance

2019 - Present | Spain

Building web applications for 15+ clients across Spain and Latin America. Started with WordPress (18+ sites for culture, legal and retail sectors), then moved into React and Node.js/Express.js for custom platforms with authentication, RESTful APIs, and real-time data sync. Led complete project lifecycles from requirements to deployment. Configured Azure cloud infrastructure for high-traffic platforms.

IT Analyst / VBA Developer - BHP Billiton

2017 - 2019 | Santiago, Chile

Developed Excel/VBA automation tools that reduced reporting time by 60%. Analyzed operational data for decision-making support in mining operations. Improved data processing efficiency for enterprise reporting systems.

Software Implementation Specialist - Corporación Venseg 18 C.A.

2015 - 2017 | Caracas, Venezuela

Implemented corporate software and trained 50+ end users. Managed technology project timelines and stakeholder communication. Coordinated software deployments across multiple departments.

Education & Certifications

  • Computer Engineering - UNEG Venezuela (2014)
  • ISTQB Foundation Level - Kumache TICS (2017)
  • IT Security Management - SEPE Spain (2023)

Skills

Frontend Development

  • React & Custom Hooks
  • Tailwind CSS & Bootstrap
  • Component Architecture
  • Responsive Design

UX & Data Visualization

  • Custom Dashboards
  • Interaction Flow Design
  • User Testing & Feedback
  • User-Centered Design

Backend Development

  • Node.js / Express.js
  • REST APIs
  • Authentication & Security
  • Real-time Data Sync

CMS & Platforms

  • WordPress (themes/plugins)
  • Shopify & Squarespace
  • E-commerce Solutions
  • CRM Integration

Contact

Email: karelys@reakagency.com

LinkedIn: linkedin.com/in/karelys-denis