Gurpreet S.

🏆 Top Rated Upwork Freelancer 🕓 25,500+ Hours Worked ⭐ 100% 5-Star Feedback ✅ Verified Portfolio Hello! 👋 I am a Senior Full Stack Developer & AI/LLM Engineer with 7+ years of experience building scalable web applications, high-performance backend systems, real-time platforms, SaaS products, casino/gaming ecosystems, and AI-powered applications. I combine strong software engineering with modern AI, LLM & Generative AI technologies to build production-ready products — from AI agents and RAG systems to complex backend architectures, real-time platforms, intelligent SaaS, and automation workflows. 🤖 AI / LLM / GenAI OpenAI/GPT, Anthropic Claude, Google Gemini & LLM APIs AI Agents, Agentic AI & Multi-Agent Systems AI Assistants, Copilots & Conversational AI RAG, Knowledge Bases & Document Q&A LangChain, LangGraph, LlamaIndex & AI SDKs Prompt & Context Engineering Function/Tool Calling & Structured Outputs Embeddings, Vector Search, Semantic & Hybrid Search AI Search & Recommendation Systems AI Automation & Intelligent Workflows Document Processing & Information Extraction Multimodal/Vision AI, Speech-to-Text & Text-to-Speech AI Memory & Context Management Model Routing & AI Orchestration LLM Evaluation, Guardrails & Observability Hallucination Reduction, Prompt Injection & AI Security LLM Cost & Latency Optimization 🚀 AI Applications I Build AI SaaS • AI Chatbots • AI Agents • RAG Systems • AI Copilots • Knowledge Assistants • Customer Support AI • Research Agents • Coding Assistants • Data Analysis Agents • Document Intelligence • AI Automation • Recommendation Engines • Intelligent Search I integrate AI with databases, REST/GraphQL APIs, CRMs, payment systems, third-party SaaS, internal tools, and real-time applications. 🎰 Casino, iGaming, Sportsbook & Gaming Strong experience building casino platforms, sportsbook systems, multiplayer games, real-time betting ecosystems, wallets, and high-concurrency gaming backends. 🚀 3 Complete Casino Platforms — Fully Built & Ready to Launch 🏛️ Land-Based Casino System — Enterprise-grade platform for physical casino operations with robust backend management and game integration. 🎫 Sweepstakes Casino Platform — Complete sweepstakes-model casino designed for rapid market entry, player engagement, retention, wallets, promotions, and scalable infrastructure. 🤝 Casino Affiliate Platform — Complete affiliate ecosystem with partner management, tracking, reporting, commissions, and acquisition workflows. 🎮 2,000+ Games Included — Large game library supporting a broad casino ecosystem and faster platform launch. Casino Expertise Slots • Blackjack • Roulette • Poker • Crash • Dice • Live Casino • Sportsbook • Odds • Betslip • Settlement • Wallets • Transactions • Bonuses • Rewards • Affiliates • Multiplayer • Game State Management • Real-Time WebSockets • Admin Dashboards • Analytics 💻 Full Stack & Backend Backend: Node.js, Express.js, NestJS, REST, GraphQL, WebSockets, SocketIO, Microservices, Event-Driven Architecture Frontend: React, Next.js, Angular, Vue, Redux, JavaScript, TypeScript, HTML5, CSS3 Database: PostgreSQL, MySQL, MongoDB, Redis, Supabase, pgvector, Vector Databases Cloud/DevOps: AWS, Google Cloud, DigitalOcean, Docker, CI/CD, GitHub Actions, Linux Tools: Jest, Mocha, Postman, Swagger/OpenAPI, Git, GitHub, GitLab, Bitbucket 💳 Payments & SaaS Stripe, Razorpay, Paytm, Braintree, Payment Gateways, Subscriptions, Recurring Billing, Webhooks, Refunds, Wallet Systems. Experience building multi-tenant SaaS, AI SaaS, RBAC, billing, admin panels, analytics, dashboards, APIs and workflow automation. 🔐 Production Engineering I focus on scalability, performance, security, reliability and clean architecture, including authentication, OAuth, JWT, RBAC, API security, rate limiting, caching, database optimization, monitoring, CI/CD, and secure AI integrations. 💡 Why Work With Me? ✅ 25,500+ Upwork hours ✅ 100% 5-star feedback ✅ Top Rated Freelancer ✅ 7+ years experience ✅ Full Stack + Backend + AI/LLM expertise ✅ Production AI Agents, RAG & automation experience ✅ 3 complete casino platforms + 2,000+ games ✅ Sportsbook, gaming & high-concurrency systems ✅ Payment, wallet & subscription expertise ✅ Clean, scalable, production-ready code ✅ Reliable communication & long-term support Whether you need an AI SaaS, LLM application, RAG chatbot, AI agent, automation platform, real-time backend, casino, sportsbook, gaming system, or complete full-stack product, I can help turn your idea into a scalable, production-ready solution. 👉 Let’s build something powerful together.