Need an AI pipeline or data platform built for production - not just a prototype? I ship end-to-end AI and data systems that handle real scale: 1M+ documents, 100+ production pipelines, 10x costs optimization. 12+ years building for DraftKings, DataRobot, Sift, and Sentra. Now I help companies turn AI proof-of-concepts into production systems that actually work. Recent solutions & projects: - Built QA framework and developer tooling for AI-powered lease extraction platform - test infrastructure for validating LLM extractions across 19 lease term categories (with 92+ test cases), plus an internal web tool for debugging, prompt reconstruction, and one-click test case generation. - Built a custom EOR (Employer of Record) classification rules engine with LLM-generated rationales, and a conversational AI assistant in front of it that turns a plain-English scenario into a recommendation while the deterministic engine stays the source of truth. - Built AI-powered search API with hybrid vector+semantic ranking (1M+ CV files across 6 brands) - Re-engineered 100+ ETL pipelines - 10x infrastructure cost reduction - Conversational analytics platform: natural language to business insights for logistics What I Build: 1. RAG & Knowledge Systems Production pipelines, vector database optimization (Azure AI Search), hybrid search with reranking, custom embeddings for domain-specific retrieval 2. LLM Integration OpenAI, Anthropic, Azure OpenAI - function calling, structured outputs, agent orchestration, prompt engineering for consistent results. Frameworks: LangChain and Microsoft Agent Framework. 3. Backends & Data Platforms FastAPI, async Python, cloud-native on AWS/Azure/GCP, data warehouses (Snowflake, BigQuery, Databricks), real-time and batch pipelines. Tech Stack: Python, FastAPI, Docker, Kubernetes, Terraform, AWS/Azure/GCP, Databricks, Snowflake Industries: Financial Services, Telecom, Data Security, Logistics, Legal, Recruitment

Full Stack Web Developer, Backend C# Developer ( Angular, React, Vue ) 🔸 20 years of experience in developing business applications software 🔸 C# | .NET Core | ASP.NET MVC | REST API | Sockets 🔸 MS SQL Server | MySQL| PostgreSQL | MongoDB 🔸 Angular 2+, JavaScript, jQuery, SignalR 🔸 Azure DevOps | AWS 🔹 HTML5 | CSS | Bootstrap 🔹 ORM: Entity Framework | NHibernate | LLBLGen 🔹 NUnit | XUnit | MSTest 🔹 Source control: Git | SVN | TFS 🔹 Self-starter and can work independently, also a great team player.

Hi. I am a Software Engineer, System Administrator and DevOps with 12+ years of professional software development experience, 22+ years of general software development and system administration. ✅ 30+ different projects outside Upwork ✅ FullStack / Full-Stack / Full Stack Developer ✅ Backend / Back-End / Back End Developer ✅ Frontend / Front-End / Front End Developer ✅ Team Lead | TeamLead ✅ Tech Lead | TechLead ✅ System Administration and DevOps experience ✅ Design and implementation of monolith applications and microservices ✅ I also have teaching experience and preparation of technical documentation ✅ If you are interested in more details and/or consulting, please ping me )

Welcome I'm Oles 🐲 Full-Stack Developer with 8 years of experience building scalable web and mobile products. I’m proficient in Next.js, React Native, and Node.js, and I focus on clean UI, efficient backend integration, and a seamless user experience. 💻 React / Next.js: development of SPAs, SSRs, and PWAs in TS/JS, well-thought-out state management, REST/GraphQL integration. Layout is semantic, responsive, and focused on accessibility. 📱 Mobile: I build cross-platform iOS/Android apps using React Native / Expo, including work with native modules, performance optimization, and push notification integration. ⚙️ Backend & DB: Node.js (Express/NestJS), API design, working with PostgreSQL, MongoDB, Supabase, query optimization, and system stability. 🚀 DevOps & processes: Docker, AWS, Vercel, CI/CD, authentication (JWT, OAuth2), logging, and security. I work in an Agile environment, cover my code with tests, and take full responsibility for features from concept to production.

Top Rated Expert with 15+ years of experience building high-performance e-commerce solutions on Upwork (200+ projects, 22,000+ hours). I specialize in integrating modern AI with WordPress to create scalable, automated workflows that drive business growth. Current Focus: - Custom Plugin Architecture & Maintenance - Enterprise Security & Performance Optimization - AI-Driven API Integrations (Social Media & Ad Platforms) What I Deliver: - AI Integration: Connect WordPress to OpenAI, Claude, and other AI services for chatbots, content generation, and smart automation - Custom API Development: Build REST API endpoints to integrate WooCommerce with CRMs, logistics platforms, and external systems - WooCommerce Deep Customization: Checkout flows, pricing rules, payment gateways, and functionality beyond standard settings - Theme & Plugin Architecture: Scalable, high-performance systems built from scratch—not off-the-shelf templates Why Work With Me: - Proven track record resolving complex technical challenges - Clear communication and structured project management - Support staff available for live meetings (English & German) Let's discuss your project. Message me to get started.

Need a marketplace developer who has actually shipped two-sided platforms? That is all we do. I lead delivery at Roobykon Software, a dedicated marketplace developer and Sharetribe developer team. I help founders build two-sided marketplaces, booking platforms, and multi-vendor marketplace MVPs, the kind that connect buyers with sellers, hosts with guests, or clients with service providers. Think Airbnb, Etsy, Turo, TaskRabbit, or Booking, built for your niche. Why founders pick me: 🔹 150+ successful marketplaces launched globally 🔹 5-week MVP delivery, from idea to a working, revenue-ready product 🔹 Trusted for 14 years in commercial delivery 🔹 Serving customers across 50+ countries (Europe, North America, and MENA) 🔹 Built SaaS trusted by 3000+ users worldwide 🔹 Scaled a Minimum-Viable-Product platform to $3M in investment 🔹 Platforms ranging from lean MVPs to multi-million-dollar ecosystems 🔹 Delivered for clients in e-learning, real estate, healthcare, rentals, and more What I build: 🔸Two-sided and multivendor marketplace platforms (Sharetribe, Sharetribe Flex, Ruby on Rails, Node, Next.js) 🔸Booking, reservation, and scheduling systems with availability management 🔸Reverse and B2B marketplaces where buyers post requests and providers apply 🔸Directory and listing platforms with map-based search 🔸Migrations and rebuilds from Bubble, WordPress, WooCommerce, Shopify, and Magento 🔸Niches I have shipped in: rentals, on-demand and gig services, home services, real estate, logistics and delivery, events and ticketing, e-learning, healthcare, wellness, and B2B and ecommerce marketplaces. Payments and marketplace mechanics we know cold: 🔹 Stripe and Stripe Connect (Standard, Express and Custom): escrow holds, commission splits, platform fees, and payouts 🔹 Multi-party and multi-currency payments, subscriptions, and tax automation (Stripe Tax, Avalara, TaxJar) 🔹 Vendor onboarding, dual user roles, admin panels, and vendor dashboards 🔹 Real-time chat, notifications, ratings and reviews, and identity verification The team behind your build: Our people cover the full stack, so you get one accountable partner instead of five freelancers. That includes Sharetribe developer, full stack developer, web developer, React developer, Angular developer, Node.js developer, and if required WordPress developer and Bubble developer skill sets, plus product and business analysis to turn your idea into a clear, buildable scope. Once launch is done, we support growth too: website development, SEO, and organic growth to bring your first users in. How we work (the value you actually get): ➜ We scope honestly: realistic timelines, no overpromises, and a straight answer on what to cut for a lean MVP. ➜ We think like product architects, recommending proven APIs and tools over custom builds wherever it saves you money. ➜ We stay transparent from discovery through QA, deployment, and post-launch optimization. ➜ We position as a partner, not a vendor: technically fluent, and honest about fit before you spend a dollar. If you are building a Sharetribe marketplace, a two-sided platform, or a marketplace MVP and want a team that has done it 150+ times, send a short message about your product. Happy to give you a straight, practical read on scope and timeline on a free consultation.

I develop AI agents, RAG systems, AI-powered document search, and workflow automation for business applications using Python, LangChain, OpenAI, Anthropic, Azure OpenAI, vector search, and modern LLM workflows. I also have 15+ years of production .NET experience with C#, ASP.NET Core, APIs, databases, cloud systems, integrations, logistics software, performance optimization, and legacy modernization. Numbers: - $80K+ earned on Upwork - 23 Upwork jobs - 1,100+ Upwork hours - 15+ years in software development - 50+ delivered software projects I can help with: - AI agents using Python, LangChain, OpenAI, Anthropic, and Azure OpenAI - RAG over documents, tickets, orders, products, reports, and knowledge bases - AI document search, semantic search, data extraction, and summarization - LLM workflows with validation, business rules, and human review - AI features inside existing .NET / ASP.NET Core applications - ASP.NET Core APIs, SaaS platforms, admin panels, and business systems - Legacy .NET Framework, ASP.NET MVC, WebForms, and VB.NET modernization - SQL performance optimization, background jobs, queues, caching, and integrations - Logistics software: TMS, WMS, order management, rate engines, shipment tracking, and carrier APIs For the AI/RAG part, I can use Python/LangChain. For production backend, APIs, admin panels, and enterprise integration, I can use .NET / ASP.NET Core. Tech stack: Python, LangChain, OpenAI, Anthropic, Azure OpenAI, RAG, embeddings, vector search, .NET, C#, ASP.NET Core, Blazor, SQL Server, PostgreSQL, MongoDB, Redis, EF Core, Dapper, Azure, AWS, RabbitMQ, Kafka.

I have 10+ years of experience as a full-stack developer and have completed over 400 web development and design projects. ⭐ Top Rated on Upwork · 100% Job Success · $100K+ Earned ★ Co-founder at Tresor.tech — Top 3% Agency on Upwork ★ Trusted by AnsaMcal, Zeppelin, GGskins, Lootbet, Crytek ★ 400+ projects delivered for Gaming niche, Web3 & classic B2B/B2C I'm Serhii, founder at Tresor.tech — a senior design and development agency specializing in Gaming platforms, Esports products, and Web3 applications. Our team includes React developers, Node.js developers, WordPress specialists, UI/UX designers, and product designers working daily in Figma, React, Next.js, and Node.js. We bring deep niche expertise across high-performance digital products: 🎮 Gaming Platform Developer | tournament systems, player portals, real-time gaming applications 🏆 Esports Platform Developer | live scoring, bracket systems, team management, competitive gaming portals 🌐 Web3 Developer | dApp frontends, DeFi dashboards, wallet integrations, GameFi products 🔧 WordPress Developer for Gaming | custom CMS for gaming operators and esports organizations ⚡ React Developer for iGaming | high-load casino interfaces, sportsbook platforms, betting products 🔩 Node.js Developer | real-time APIs, gaming backends, scalable Web3 platform architecture These vertical development skills run through every project — allowing us to solve industry-specific technical challenges with precision. 🧑‍💻 Our Team We have 20+ senior specialists including: ✔️ React / Next.js Developers for Gaming, Web3, and SaaS platforms ✔️ Node.js Developers building scalable backends and real-time APIs ✔️ WordPress Developers for custom CMS and plugin development ✔️ UI/UX Designers that create complete product from wireframe to Figma ✔️ Full-Stack Developers covering frontend, backend, DevOps, and API integrations Whether you need a Gaming Platform Developer, a Web3 React Developer, a WordPress Developer for Gaming, or a full-stack agency team — we cover the entire development and design stack. 💼 Experience & Strengths Across 400+ completed projects, we've built Gaming platforms, Esports portals, Web3 dApps, iGaming interfaces, WordPress sites, and SaaS dashboards. Our developers and designers collaborate closely to deliver production-ready products — on time, clean code, no juniors. We frequently serve clients requiring specialized expertise such as: Gaming Platform Developer for tournament and player-facing systems Esports Platform Developer for competitive gaming organizations Web3 React Developer for DeFi and blockchain applications WordPress Developer for Gaming operators and media platforms Node.js Developer for real-time Gaming and Web3 backends iGaming Developer for casino, sportsbook, and betting platforms All development is built on React, Next.js, Node.js, and WordPress — with Figma design systems and full developer handoff included. 💎 Who We Serve ✔️ iGaming operators and online casino platforms ✔️ Esports organizations and tournament operators ✔️ Web3 startups — DeFi, GameFi, dApp products ✔️ Gaming studios and game platform companies ✔️ Skin battle and CS2 case platform operators ✔️ SaaS and B2B platforms needing senior full-stack execution ✔️ Western agencies needing a white-label dev & design partner 🛠️ Our Services ✦ Gaming & Esports Platform Development React/Next.js frontends for tournament systems, player portals, live scoring, team pages, and gaming community platforms. Full-stack delivery from Figma to production. ✦ Web3 & Crypto Development dApp frontends, DeFi dashboard development, wallet integrations, staking UIs, and GameFi products. React + Web3.js + Node.js stack. ✦ WordPress Development for Gaming & SaaS Custom WordPress builds — ACF Pro, WPForms, WP Rocket, Yoast SEO. Gaming media platforms, affiliate sites, operator CMS solutions. ✦ UI/UX Design + Development Full-cycle: Figma design system → React/Next.js implementation. No handoff delays. Design and dev in one team. ✦ CRO & Performance Optimization Conversion-focused rebuilds for Gaming operators and Web3 platforms. Core Web Vitals, load speed, retention mechanics. 🔧 Our Process ✔ Discovery & Technical Scoping ✔ UI/UX Design in Figma ✔ React / Next.js / WordPress Development ✔ API Integration & Backend Development ✔ QA & Performance Testing ✔ Launch & Ongoing Support 🔥 My Expertise Specialized niches: Gaming Platform Developer, Esports Platform Developer, Web3 React Developer, WordPress Developer for Gaming, iGaming Developer, Node.js Developer for real-time platforms, Skin Battle Platform Developer, GameFi Developer Industries served: Gaming, iGaming, Esports, Web3, DeFi, Crypto, SaaS, Skin Battle Platforms, GameFi, WordPress CMS. → Message me or book a free 30-min discovery call — we respond within 6 hours.

✅ 𝗧𝗼𝗽 𝟭% 𝗨𝗽𝘄𝗼𝗿𝗸 Web Developer | 𝗧𝗼𝗽 𝗥𝗮𝘁𝗲𝗱 𝗣𝗹𝘂𝘀 🏆 • 𝟭𝟱+ 𝘆𝗿𝘀 𝗼𝗳 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲, • more than hundred 𝟱 𝘀𝘁𝗮𝗿 proven feedbacks at UpWork • 4400+ working hours at UpWork i’m Experienced Senior Web Developer. I build fast, secure, and scalable websites using HTML, JavaScript, PHP, WordPress and Web Design. My focus is on delivering solutions that drive measurable business results: — Custom WordPress development (themes, plugins, WooCommerce integration). — Frontend development with clean, responsive HTML/CSS and modern JavaScript. — Backend solutions in PHP for dynamic and high‑performance applications. — Speed optimization (90+ Google PageSpeed) and SEO‑ready architecture. With 15+ years of experience and 100+ successful projects for clients across the US and Europe, I combine technical expertise with business understanding. My goal is not just to code a website, but to create a digital product that helps you grow. i’m certified WordPress developer by TemplateMonster certification.templatemonster .com/certificates/c1e72582ddfb2a2af92277df25392a44/ My skills: ✅Html5, Css3, Bootstrap - 15 years of exp ✅Php - 12 years of experience ✅React - 7 years of experience ✅Node.js - 5 years of experience ✅JavaScript - 14 years of experience ✅WordPress - 15 years of experience ✅WooCommerce - 10 years of experience ✅Web Design - Figma/XD/PSD - 12 years of experience 𝗥𝗲𝗮𝗱𝘆 𝘁𝗼 𝗝𝗼𝗶𝗻 𝟭𝟬𝟬+ 𝗦𝗮𝘁𝗶𝘀𝗳𝗶𝗲𝗱 𝗖𝗹𝗶𝗲𝗻𝘁𝘀? Click on the 𝗠𝗲𝘀𝘀𝗮𝗴𝗲 or 𝗜𝗻𝘃𝗶𝘁𝗲 𝘁𝗼 𝗝𝗼𝗯 button on top-right corner. 🤝 Some more of my Website and Web App Development skils: Website development: ✅Web Design - Figma/XD/PSD ✅Html5, Css3, Bootstrap ✅Php ✅React ✅WordPress website development ✅WordPress custom theme development ✅WordPress custom plugin development ✅WordPress api integration E-Commerce development: ✅WooCommerce custom development ✅Craft CMS development ✅Shopify development ✅Shopify Pro development ✅Wix website development ✅Magento custom development ✅Joomla website development ✅PrestaShop development Web Application development: ✅Laravel development ✅React js development ✅MERN stack development ✅JavaScript (ES6) development ✅TypeScript development Backend development: ✅Node.js development ✅Ruby on Rails development ✅Python development ✅Php development Moblie App development: ✅React Native development ✅Flutter development ✅iOS native development ✅Android native development ⭐️⭐️⭐️⭐️⭐️My most famous clients: NINTENDO, BOSS Audio, ICVR io ⭐️⭐️⭐️⭐️⭐️i developing websites and apps that gives 🎯 PROFIT for my clients. ⭐️⭐️⭐️⭐️⭐️After starting our collaboration revenue of my clients grow by 🎯 $30M per year There are 100+ REAL 𝗧𝗲𝘀𝘁𝗶𝗺𝗼𝗻𝗶𝗮𝗹𝘀 showing why clients trust me to build their websites and apps. Want to 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 𝗶𝘁 𝘆𝗼𝘂𝗿𝘀𝗲𝗹𝗳? Click on the 𝗠𝗲𝘀𝘀𝗮𝗴𝗲 or 𝗜𝗻𝘃𝗶𝘁𝗲 button and let’s start 🤝 Keywords: Website Development, Website Development for Startup, MVP Development, Frontend Developer, Frontend Engineer, Frontend Dev, Front End Developer, Backend Developer, Full-Stack Developer, Wordpress Custom Development, Wordpress Plugin Developer, Wordpress ACF Developer, WooCommerce Custom Developer, WooCommerce Developer, HTML Developer, HTML/CSS Developer, HTML Website, Web App Development, Wordpress Page Speed Optimisation, WordPress Performance Optimisation , Chart.js, D3.js, React Developer, React.js Developer, Magento Developer, Figma to Html, Figma to WordPress, Small Business Website, Middle Business Website, Landing Page Development, Web Design, Web Designer

Hello there, I'm a seasoned web developer hailing from Ukraine with a wealth of experience in both corporate settings and now as a dedicated freelancer. My journey began with crafting themes and plugins for websites within company environments, but I've since transitioned to freelance work where I've honed my skills even further. My expertise spans various facets of web development, with a particular focus on ecommerce projects and landing page optimization. I specialize in JavaScript and PHP, adept at breathing life into websites with seamless functionality and dynamic features. Whether it's crafting layouts from PSD templates or ensuring pixel-perfect precision, I take pride in delivering work that exceeds expectations. Over the years, I've delved into the intricacies of site optimization for improved Google rankings and accessibility, while also delving into the realm of SEO-friendly HTML and meta tag creation for enhanced social media visibility. Since 2018, I've embraced technologies like Laravel and VueJS, leveraging them to tackle complex projects ranging from server-rendered applications to API integration and data management. My skill set extends across a wide array of technologies, including: Technologies: - PHP 7+ -- Laravel -- Elastic search -- Wordpress ( creating themes and plugins ) -- WooCommerce -- Redis -- Custom scripts -- VM -- Docker -- bash scripts - Javascript -- VueJs -- Nuxt -- JQuery -- AngularJS -- Vuetify -- Quasar -- Cordova -- ChartJS - Databases -- Mysql -- Postgresql -- MongoDB - Design -- Html5 -- Css -- Sass / Scss -- Bootstrap -- Material design -- Pixel perfect codding -- Seo murcup -APIs -- Amazon Product Advertising API 5.0 -- Avantlink -- Google maps -- Google analytics -- IMDb (and same) -- TelegramAPI -- SteamAPI -- Google tag manager