I am a senior full-stack developer with more than 25 years of experience in web and interactive media. I have led development teams, started companies, and driven innovative projects that mix technologies to deliver high-performance, secure systems. In the last decade I’ve worked mostly on contract roles with major agencies in Denmark, leading concept development, architecture, and hands-on implementation for large-scale, customer-facing platforms. Recently I relocated to Silicon Valley to work on a healthcare startup, serving as system architect and lead developer to shape information architecture, UX, and the technical strategy. I thrive in collaborative environments, talking with stakeholders to crystallize requirements into technical plans and delivering robust, scalable solutions.

Sonny Eintsen

I am a senior full-stack developer with more than 25 years of experience in web and interactive media. I have led development teams, started companies, and driven innovative projects that mix technologies to deliver high-performance, secure systems. In the last decade I’ve worked mostly on contract roles with major agencies in Denmark, leading concept development, architecture, and hands-on implementation for large-scale, customer-facing platforms. Recently I relocated to Silicon Valley to work on a healthcare startup, serving as system architect and lead developer to shape information architecture, UX, and the technical strategy. I thrive in collaborative environments, talking with stakeholders to crystallize requirements into technical plans and delivering robust, scalable solutions.

Available to hire

I am a senior full-stack developer with more than 25 years of experience in web and interactive media. I have led development teams, started companies, and driven innovative projects that mix technologies to deliver high-performance, secure systems. In the last decade I’ve worked mostly on contract roles with major agencies in Denmark, leading concept development, architecture, and hands-on implementation for large-scale, customer-facing platforms.

Recently I relocated to Silicon Valley to work on a healthcare startup, serving as system architect and lead developer to shape information architecture, UX, and the technical strategy. I thrive in collaborative environments, talking with stakeholders to crystallize requirements into technical plans and delivering robust, scalable solutions.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
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Language

Danish
Fluent
English
Fluent
Spanish; Castilian
Intermediate

Work Experience

Fullstack Developer at Loudcode / Silicon Valley startup
September 1, 2024 - Present
System architect and lead developer for a healthcare platform; responsible for information architecture, UX conceptualization, and end-to-end implementation. Backend stack includes Node.js, NestJS, and Fastify; frontend using Next.js. Contract-based engagement with handover planned at launch.
Full Stack Lead Developer at Zoetis
October 1, 2022 - September 30, 2024
Led development across multiple services and websites for Zoetis, the world’s largest animal health company. Technologies include React.js / Next.js, Node.js, NestJs, REST API, WebSockets, with CI/CD practices across services.
Full Stack Developer (Freelance) at Various Danish Brands (Freelance)
February 1, 2022 - October 31, 2022
Full stack development on two large-scale ecommerce projects; frontend work for a headless CMS; system integration and ongoing maintenance.
Full Stack Developer at Novo Nordisk
November 1, 2021 - February 28, 2022
Full stack development on the Selina research system; React.js frontend, Node.js/Express backend, REST API, CI/CD, and AWS cloud integration.
Mobile App Developer at FDM
March 1, 2021 - July 31, 2021
React Native mobile app development for a major Danish organization; setup included a full CI/CD pipeline via MS App Center.
Fullstack Developer at NNIT
September 1, 2019 - January 31, 2021
Maintained and evolved a large legacy platform; worked across Vue, Angular, React front-ends and PHP-based back-end services; API development and general server-side work.
Frontend Developer / React at TDC, YouSee / Nuuday
May 1, 2018 - September 30, 2019
React frontend development for mission-critical core systems; DevOps collaboration, Docker usage, automated tests, and CI/CD. Initially contributed as PHP backend services before moving to frontend focus.
Fullstack Developer at Startup (Restaurants Platform)
January 1, 2018 - December 31, 2018
Lead developer for a restaurant/customer platform; backend with Phalcon PHP and REST APIs; React Native mobile apps; focused on performance and scalable design.
Fullstack Developer / System Architect at LogLevel
January 1, 2017 - December 31, 2018
Led development of a competence management system for airlines and IT sectors; built with PHP MVC (Phalcon), Docker-based DevOps, and high-performance front-end rendering using D3.
Founder, Partner & Lead Developer at Loudcode
January 1, 2004 - December 31, 2017
Founder and leader of Loudcode in Barcelona; responsible for architecture, development, and delivery of a broad range of websites and systems for large brands, startups, and portals. Built an in-house team and steered multiple high-profile projects.
Fullstack Developer at Freelance / Various Projects
January 1, 2002 - December 31, 2004
Freelance development on large-scale projects, including SAAS platform for TDC A/S, youth web community portals, Telia portal, and other major web initiatives.
Fullstack Developer at CBS Copenhagen Business School
January 1, 2001 - December 31, 2002
Web development for North Europe’s largest business university; development of the official portal used by students to manage education tasks, subject selection, and virtual study groups.
Technical Manager - Web Technologies at Pomelo A/S
January 1, 2001 - December 31, 2001
Technical leadership for web technologies for an European startup; web design, architecture decisions, and project management.
Frontend Developer at Framfab
January 1, 2000 - December 31, 2001
Interface development for large-scale projects; worked on Dan mak banking and Maersk-scale sites among others.
Manager for Web Agency at Telia
January 1, 1996 - December 31, 2000
Founded and led a web agency, recruiting and managing developers; produced more than 400 websites for Danish SMEs, overseeing production, planning, and education.
Fullstack Developer at Silicon Valley Startup (Healthcare)
September 1, 2024 - Present
System architect and lead developer responsible for designing the platform architecture (Node.js/NestJS/Fastify on the backend and Next.js on the frontend), defining information structure and UX concepts, and driving technical delivery for launch and handover.
Full Stack Developer at Zoetis
October 1, 2022 - September 30, 2024
Lead full-stack developer on multiple services and websites for a global animal health company; collaborated across teams to deliver scalable web services and interfaces with REST API and WebSocket support.
Full Stack Developer at Freelance
February 1, 2022 - October 31, 2022
Delivered two large-scale e-commerce projects for major Danish brands, contributed to frontend development for a headless CMS, and provided end-to-end implementation for critical client platforms.
Frontend Developer at TDC / YouSee / Nuuday
May 1, 2018 - September 30, 2019
Contributed to mission-critical core systems; worked in a DevOps-driven team with Docker, automated tests, CI/CD; initially back-end PHP, then React frontend.
Fullstack + Mobile Developer at Startup (Copenhagen)
January 1, 2018 - December 31, 2018
Lead developer for restaurant and customer-facing solutions; built mobile apps with React Native and back-end APIs (Phalcon PHP).
Fullstack Developer at LogLevel
January 1, 2017 - December 31, 2018
Led development and system architecture for a competence management system; implemented Docker, GitLab CI/CD and modern PHP MVC architecture.
Founder / Manager at Loudcode
January 1, 2004 - December 31, 2017
Founder, partner and lead developer. Built and managed Loudcode from 2004 to 2017 in Barcelona; delivered a range of high-performance web platforms and startup-driven projects for major brands; led architecture, UX discussions and business collaboration.
Freelance Fullstack Developer at Freelance (Copenhagen)
January 1, 2002 - December 31, 2004
Delivered freelance full-stack work on large-scale projects, including a SaaS platform for a major Danish telecom and a large youth web community portal.
Fullstack Developer at Pomelo A/S
January 1, 2001 - December 31, 2001
Web development and technical leadership for European startup initiatives; defined web solutions and technical strategies.
Manager for Web Agency, Plus Developer at Telia
January 1, 1996 - December 31, 2000
Founded and managed a web agency, recruiting and leading a team; delivered hundreds of websites for Danish SMEs.

Education

Add your educational history here.

Qualifications

Industry Experience

Software & Internet, Healthcare, Professional Services, Education, Telecommunications, Media & Entertainment, Life Sciences, Retail, Consumer Goods, Other

Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
See more