09/18/2026 updated
100 % available
FullStack Engineer & Tech Lead - AI, SaaS, Next.js
Luxembourg, Luxembourg
Germany +7
DAW + Bootcampsinfo: Germany, Switzerland, Spain, France, Belgium, Luxembourg, Netherlands, Spain (Canary Islands)
About me
Senior fullstack engineer and tech lead in Luxembourg. 30+ digital products from idea to production for IKEA, EDP, Fintonic, Adevinta and more, including AI features. TypeScript, Next.js, React Native, Node, PostgreSQL, Kubernetes. Remote or hybrid, on-site in Luxembourg. English and Spanish.
AI AgentsRAGGitHub ActionsGenAILLMJavaScriptAtlassian JiraMobile Application DevelopmentSoftware as a ServiceDevOpsGitHubPostgreSQLNode.jsSoftware ArchitectureNext.js
Frontend Development with React & Next.js
Expertise in building modern web and mobile applications using TypeScript, JavaScript, React, Next.js, React Native and Expo. Extensive experience in design systems, component libraries with Storybook, and internationalisation for multi-market products.
Software Architecture & Technical Leadership
Deep knowledge in software architecture, technical leadership and product engineering. End-to-end ownership of products from business problem definition to production delivery, including engineering standards, code quality and delivery processes.
Cloud Infrastructure & DevOps
Hands-on experience with Docker, Kubernetes, CI/CD pipelines and GitHub Actions. Management of own infrastructure including monitoring, backups and Sentry for observability, as well as integration of AI features with language models in production.
Backend & Database Technologies
Proficiency in PostgreSQL, Prisma, Supabase, Firebase, Redis, WebSocket and Stripe for building robust backend systems and data layers.
Testing & Quality Assurance
Experience with Playwright, Jest, Cypress and Maestro for automated testing across web and mobile.
Conversion Rate Optimisation (CRO)
Practical application of CRO techniques including A/B testing with Google Optimize, measuring and optimising user flows and business logic on live production sites.
Applied AI & Large Language Models
Integration of AI features and language models into production applications, including real-time interfaces for ML-based conflict prevention and real-time data processing.
Technical SEO
Knowledge and application of technical SEO best practices within web product development to improve search engine visibility and performance.
Full Stack Web & Mobile Development
Delivery of custom web and mobile products for companies and startups, covering technical design, production deployment and ongoing maintenance using Node.js and related technologies.
Experience
Professional experience10+ years
Freelancer since2020
Languages
EnglishFluentSpanishNative speaker
Project history
Custom software company in Madrid and Luxembourg. Leading the technical direction, architecture and delivery of every product, from requirements to production. Architecture and delivery of web, mobile and backend products for multiple clients. Engineering standards, code quality and delivery process for a fully senior team. Own infrastructure on Kubernetes with CI/CD, monitoring and backups. AI features with language models in production.
Digital product consultancy. Tech Lead for the new web platform and CMS of an international pharmaceutical company. Responsible for frontend architecture, CMS integration and coding standards. Internationalisation by country and language for a single multi-market product.
Custom web and mobile products for companies and startups, from technical design to production, deployment and maintenance included. Synkross grew out of this work.