I'm a full-stack developer, engineering leader, and CTO with over a decade of experience building end-to-end systems, AI infrastructure, and products at the intersection of technology, sustainability, and design. I specialize in creating scalable, user-centric applications with modern tech stacks, from frontend interfaces to backend services and infrastructure.

• 🌱 CTO role: Building AI-based platforms for grid optimization
• ⚡ Learning: AI Agents (LangGraph, n8n, Zapier), Federated Learning
• 💬 Expertise: Full-stack architecture, AI pipelines, startup strategy, MVP development

Led and contributed to multiple full-stack projects serving 20,000+ students and staff:

• Lead Full-Stack Developer for comprehensive course management system

• Key Projects:

  • kurs-pm-data-admin-web — Full-stack application with ReactJS frontend, NodeJS/Express backend, and TinyMCE integration. Built complex state management for multiple editors, implemented real-time updates, and designed scalable data structures. 1,062 commits: 467,337++ 177,567--

  • kursinfo-admin-web — Full-stack solution with ReactJS frontend, NodeJS/Express backend, and OAuth integration. Developed from scratch, implementing secure authentication, real-time preview, and efficient data management. 781 commits: 158,710 ++ 414,791 --

  • kursinfo-web — Full-stack platform serving 20,000+ students with React frontend and NodeJS backend. Implemented responsive design, accessibility features, and optimized performance. 450 commits: 90,271 ++ 271,339 --

  • kopps-public-react-web — Full-stack application with React frontend and NodeJS/Express backend. Built advanced search functionality, course filtering, and program management. 337 commits: 56,058++ 54,522--

• Technical Lead and API developer for core backend services and API architecture

• Key Projects:

  • kurs-pm-data-api — RESTful API service with NodeJS/Express, implementing complex data models, caching, and rate limiting. 203 commits: 41,769++ 32,210--

  • kursinfo-api — MongoDB-based API service with NodeJS, handling data aggregation, authentication, and real-time updates. 61 commits: 19,095 ++ 12,450 --

  • kursstatistik-api — Secure API with stunnel connection to central course database, secure Dockerfile with ubuntu, ibm_db and running as a non-root user, implementing data validation and transformation. 41 commits: 12,208++ 13,526--

• Developed a secure authentication system using BankID for all students and employees (private repo)
• Created another implementation of BankID with websocket-based client-server communication to listen when the end-user authenticated with BankID: BankId with websockets - Full-stack solution with React frontend, NodeJS backend, BankID integration, and dynamic QR code generation

Building end-to-end AI solutions with modern tech stacks:

• financial-ai-agent — Full-stack financial analysis platform with LangGraph, React frontend, and Python backend. Features competitor research and interactive feedback loops.
• ai-agent-simple — Complete AI agent system with LangGraph, SQLite persistence, and RESTful API endpoints to OpenAI and Tavily Search.
• memagent-json — A simple agent implementation with JSON-based memory persistence and API integration with OpenAI (under development)

• Full-stack low-code workflow automation using n8n, LangChain, Vertex AI, Zapier
• End-to-end AI pipeline development and optimization
• Grid optimization systems with real-time monitoring

• Frontend: React, JavaScript, TypeScript, Styled Components, Webpack, Redux
• Backend: Node.js, Express/Koa, Python, RESTful APIs, WebSockets
• Database: MongoDB, SQLite, Redis, GraphQL
• DevOps: Docker, CI/CD, Google Cloud, Azure
• AI/ML: LangChain, LangGraph, Vertex AI, Custom AI Agents

• 13+ full-stack repositories contributed to across frontend, backend, and infrastructure
• Multi-year involvement in core systems with significant impact
• Consistent contributor: 2-6 commits/week on core projects
• Cross-functional leadership: Delivering both internal tooling and end-user platforms

• GitHub: lenaar