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✅ 100% Job Success | 💎 1,000+ Hours on Upwork | 🚀 MVP in Weeks, Not Months Ex-CTO | AI × Next.js / React / Node.js Architect | 19+ Years Shipping at Scale I build production-ready, AI-powered web applications that scale to millions and convert like crazy using Next.js 14+ (App Router), React 18 + TypeScript, Node.js microservices, and the latest LLMs (OpenAI, Anthropic Claude, Gemini, Llama 3, Mistral). As former CTO I’ve led teams that delivered real-time lead-generation engines, intelligent marketing platforms, and AI-enhanced SaaS products. Clients I've worked for include Toyota, Unilever, Amazon, Procter & Gamble, The North Face, American Express, and WWF. What I deliver today (end-to-end, pixel-perfect, 95–100 Lighthouse): - Next.js 14+ apps with Server Components, Server Actions, ISR/SSR, and edge deployment (Vercel + AWS) - AI features: RAG pipelines, agentic workflows, LLM-powered chat/assistants, smart scoring engines, voice agents (ElevenLabs), document intelligence - React + TypeScript frontends with tRPC, React Query, Zod, and Tailwind CSS - Scalable Node.js backends (NestJS/Fastify), PostgreSQL/Prisma, Redis, WebSockets, GraphQL, Docker + Kubernetes-ready - Full lifecycle: architecture → UX wireframes → secure code → CI/CD → monitoring & A/B testing Recent wins for clients: - Real-time lead distribution dashboard handling 50K+ events/day with AI scoring - Next.js + Claude-powered dynamic landing-page CMS (40%+ conversion lift) - Legacy PHP → modern Next.js/React migration (load time 6s → <1s) - AI agent that qualifies & routes leads automatically (saved clients $400K+/yr) Available immediately for: - React / Next.js projects - LLM integrations into existing React/Node apps - Performance & architecture audits / rescue missions - Fractional CTO + hands-on development Daily stack: Next.js 14 • React 18 • TypeScript • Node.js • OpenAI • Anthropic • Gemini • Llama • ElevenLabs • tRPC • Prisma • PostgreSQL • Redis • Tailwind • Vercel • Docker • AWS Ready to turn your idea into an AI-first, revenue-generating product fast. Message me and let’s ship something exceptional.

I help startups, founders, and businesses build scalable SaaS applications, AI-powered products, and production-ready MVPs using modern web technologies. Whether you're validating a new idea, launching a SaaS platform, or improving an existing application, I build secure, high-performance software with clean, maintainable code. Services SaaS Application Development Build scalable SaaS platforms with multi-tenant architecture, user authentication, dashboards, admin panels, role-based access control (RBAC), and subscription management. MVP Development Develop production-ready Minimum Viable Products (MVPs) that are fast to launch, easy to scale, and built with clean architecture. Full-Stack Web Development Develop responsive web applications using Next.js, React, TypeScript, JavaScript, Node.js, Express.js, NestJS, REST APIs, GraphQL, and modern frontend architecture. Supabase Development Build secure applications with Supabase Authentication, PostgreSQL, Row Level Security (RLS), Edge Functions, Realtime, Storage, Database Design, and Supabase APIs. Stripe Integration Implement Stripe subscriptions, recurring payments, checkout sessions, customer portals, invoices, payment intents, webhooks, and billing automation. AI Application Development Integrate OpenAI API, GPT-4o, AI chatbots, AI assistants, Retrieval-Augmented Generation (RAG), embeddings, vector databases, semantic search, AI workflow automation, document processing, and custom LLM applications. API Development & Integrations Develop REST APIs, GraphQL APIs, third-party integrations, webhooks, OAuth authentication, payment gateways, Twilio, SendGrid, Resend, Plaid, Google APIs, and external API integrations. Database Design Design scalable PostgreSQL, Supabase, Prisma ORM, MongoDB, and Redis databases with optimized queries and secure data access. My Development Process Understand your business requirements and product goals. Design a scalable application architecture, database schema, authentication flow, and API structure. Develop clean, reusable, and maintainable TypeScript code following industry best practices. Test, optimize, deploy, and support your application for long-term growth. Tech Stack Frontend Next.js, React.js, TypeScript, JavaScript (ES6+), Tailwind CSS, HTML5, CSS3, shadcn/ui, Material UI, Redux, Zustand Backend Node.js, NestJS, Express.js, Serverless Functions, Edge Functions, REST API, GraphQL, WebSockets Database Supabase, PostgreSQL, Prisma ORM, MongoDB, Redis, SQL, Database Design, Row Level Security (RLS), Role-Based Access Control (RBAC) AI OpenAI API, GPT-4o, ChatGPT, AI Agents, LLM Applications, RAG, Embeddings, Vector Database, AI Automation Payments & Integrations Stripe, Stripe Billing, Stripe Connect, Stripe Webhooks, Twilio, SendGrid, Resend, Plaid, OAuth, Firebase DevOps Vercel, Docker, Git, GitHub, GitHub Actions, CI/CD, Railway, Render, AWS S3 Why Work With Me * Scalable SaaS architecture * Clean and maintainable code * Secure authentication and authorization * Stripe payment integration * AI-powered application development * Fast communication and reliable delivery * Performance optimization and SEO-friendly applications * Long-term support and feature development If you need a Next.js developer, React developer, Supabase developer, Full-Stack JavaScript developer, TypeScript developer, AI developer, OpenAI developer, or SaaS MVP developer, I'd be happy to help bring your product to life.

I spent the greater part of the last 18 years working on web and mobile app development to help businesses and entrepreneurs provide services that set them apart from their competitors. The 'do more with less' approach I take in designing solutions aims to empower clients to achieve higher levels of profitability, recapture time and resources previously consumed by inefficiency, and invest those gains in any way they see fit. Technically speaking, I primarily work with the following development stack: - HTML5, CSS3/SASS/LESS/Stylus, Twitter Bootstrap/Bulma - React, Vue, AureliaJS, Backbone, Ember - Node.js/Express.js, Laravel framework, CodeIgniter, ASP.NET, Ruby on Rails - Wordpress, Drupal, Magento - Contentful CMS, Netlify CMS - MySQL, PostgresSQL, MongoDB, FirebaseDB, DynamoDB, AzureDB - Objective C, Swift, Android - React Native, Flutter - Ionic, PhoneGap - AWS, Digital Ocean, Heroku - Webpack, Gulp, Grunt - Jasmine, Mocha, Chai, Enzyme If you are looking for a developer that's truly an expert, driven by passion, not afraid to take on a challenge, I will be there with you every step of the way then look no further as I am your guy. Thanks, Dirk-Jan

Have a solid trading idea but exhausted by manual execution? I specialize in transforming your strategy into a fully automated trading bot or market scanner—engineered for accuracy, consistency, and discipline. No emotions. No missed setups. I don’t sell trading strategies or promise profits. Instead, I help traders and investors systematically build, test, and deploy their own ideas as reliable, automated solutions. 1. Custom Trading Bots (Your Strategy → Fully Automated) - Precise implementation of your entry and exit rules - Robust risk management: stop loss, take profit, position sizing, equity-based scaling - Integration with APIs such as Schwab, Interactive Brokers, Alpaca, Polygon, Finnhub, Yahoo Finance, and more - 24/7 operation with secure, cloud-based deployment for maximum reliability 2. Market Scanners & Screeners - Real-time alerts when your strategy criteria are met - Multi-timeframe confirmation (daily, weekly, monthly) - Technical filters including RSI, MACD, Heikin Ashi, volume anomalies, moving averages, and more - Fundamental-based screeners for targeted stock selection 3. Strategy Research & Backtesting - Comprehensive historical backtesting to validate ideas before live deployment - Detailed performance reports: win rate, drawdowns, profit factor, Sharpe ratio, and additional metrics - Parameter optimization and fine-tuning to improve robustness 4. End-to-End Platform Development - Web & Mobile & desktop applications (Flutter: iOS, Android, Windows, macOS) - Scalable backend automation using AWS (Lambda, API Gateway, DynamoDB, EC2) - Custom dashboards to monitor bot activity and trading performance in real time Let’s Collaborate I’m excited to bring your ideas to life with accuracy, discipline, and technical excellence. Reach out anytime to discuss how I can support your next project. Also I’ve been living in Java’s world long enough to make the JVM behave on command. I build stuff that runs fast, scales cleanly, and doesn’t fall apart under pressure — from Spring Boot microservices to data pipelines and API backends. I’m all about clean code, solid architecture, and squeezing every bit of performance out of the system. If your Java project needs a steady hand and a bit of attitude, I’ve got you covered.

Welcome to my profile, I specialize in building production-ready applications that handle real-world complexity—from real-time data processing and multi-tenant SaaS architectures to secure payment integrations and high-traffic scalability. My experience comes from developing systems where performance, security, and reliability directly impact business operations and user trust. I’ve engineered end-to-end platforms for healthcare administration, clinic management, dating, and e-commerce, with a focus on solving deep technical challenges. This includes implementing real-time dashboards with WebSocket-driven updates, designing atomic transaction flows for financial operations, and building role-based access control for sensitive data. On the backend, I architect robust systems using Laravel, Node.js (NestJS), and PostgreSQL, with attention to query optimization, connection pooling, and background job processing. I have built: - Real-time admin dashboards with live metrics using WebSockets (SocketIO) and Highcharts - Multi-tenant SaaS platforms with isolated data, subscription billing, and automated invoicing - Secure payment pipelines with Stripe, including subscription management and PCI-compliant workflows - High-performance APIs supporting real-time chat, calendar scheduling, and inventory synchronization I implement security at every layer: JWT/OAuth 2.0 authentication, encrypted data storage, audit logging, and rate limiting. I structure applications to maintain uptime during traffic spikes, using caching strategies (Redis), queue workers, and efficient database indexing. On the frontend, I build responsive, pixel-perfect interfaces with React, Next.js, or Vue, using Tailwind CSS and component libraries like Shadcn UI. I focus on delivering fast, accessible user experiences—whether for real-time dashboards, interactive booking systems, or complex admin panels—while maintaining strict design fidelity and Core Web Vitals. My approach is product-focused and detail-oriented. I prioritize clean, maintainable code, thorough documentation, and infrastructure that scales. I’m comfortable migrating legacy systems, optimizing slow queries, and debugging production issues in high-stakes environments. If you’re looking for a developer who understands both technical implementation and business impact—and can deliver secure, scalable systems from concept to deployment—I’m ready to help. Thanks