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⚡ High-Velocity Developer | 100% Success Rate Need results yesterday? I specialize in rapid, high-quality development powered by 15+ years of expertise and modern AI-assisted workflows. I combine the seasoned intuition of a veteran developer with the speed of today’s best tech. Proven: 100% Job Success Score. Fast: Optimized delivery cycles. Smart: Deep AI integration to 10x productivity and feature set. My technical expertise is extensive, encompassing PHP, Symfony / Laravel Framework, MySQL, and noSQL Databases (MongoDB, Redis). I'm proficient in node.js (socket IO framework, express), and JavaScript (Stencil JS, Ionic, React), and have built APIs using common architectures such as REST and GraphQL. Additionally, I bring to the table experience in managing AWS infrastructure and other servers based on the Linux Operating System specifically for hosting PHP / Symfony projects. My portfolio also includes building HTML mobile apps (Hybrid apps in frameworks like Ionic/Cordova). I’ve worked across a range of industries, including e-commerce, affiliate marketing, real estate, automotive, aviation, courier services, and healthcare. I have very good knowledge of Symfony Components, Doctrine ORM, PSR standards. I have also used across various projects Easy Admin, API Platform, DomPDF, Guzzle, SwiftMailer, Contao CMS and Amazon SP-API libraries. I have experience working with big data solutions - BigQuery, Adverity Datatap, building continuous cost-effective scraping solution and reliable process automations using make com (formerly integromat) Particularly, my most recent projects have been centered around the Symfony framework, granting me continuous and profound expertise in the Symfony / PHP ecosystem. My grasp of software development techniques is solid, including writing clean and secure code, object-oriented development, and designing application architecture with a focus on extensibility and scalability. I have recent experience in building projects that integrate AI features through the OpenAI / Fal APIs. For some significant period of time i was reponsible for building and maintaining shopify websites, including building custom theme, plugins that were enriching logically Shopify and also checkout cusotmisations Beyond just development, I make it a point to grasp a thorough understanding of the entire project from the end user's perspective. My years of experience enable me to provide accurate insights and advice on enhancing your project. What excites me most is problem-solving. I thrive on unraveling complex, challenging issues, and the software industry continually nurtures my knowledge and creativity. I'm also a fan of machine learning, possessing experience in Octave and the R language, along with theoretical knowledge in machine learning techniques. Recently, I have gained experience in building apps utilizing OpenAI APIs, further broadening my skill set. I take pride in being a versatile “one-man army” in Full Stack Development, capable of delivering fast, reliable results. My goal is to handle all your development needs efficiently - so you can stay focused, worry-free. I'm on the lookout for new challenges. If you're interested in working with me, I'd be eager to discuss how I can contribute to your project. Paweł

Hello! I’m Alexander, a full-stack developer with 15+ years of experience in delivering high-quality web and mobile applications. Also I specialize in API development and integrations, building seamless connections across platforms and systems. With over 150 successful projects completed worldwide, I focus on delivering scalable, secure, and business-oriented solutions. 𝗛𝗘𝗥𝗘'𝗦 𝗪𝗛𝗔𝗧 𝗜 𝗖𝗔𝗡 𝗛𝗘𝗟𝗣 𝗬𝗢𝗨 𝗪𝗜𝗧𝗛: • Custom CRM & ERP systems • B2B SaaS platforms • Fintech apps with Stripe & banking APIs • E-commerce (multi-vendor, subscriptions, headless) • Marketplaces (services, rentals, auctions) • Admin panels & internal dashboards • API development & integrations (REST / OpenAPI) • Real-time apps (chat, notifications, live data) • Booking & appointment systems • HIPAA/GDPR-compliant web platforms • AI tools (ChatGPT, OCR, automations) • SEO-optimized multilingual corporate websites • Web portals with roles & permissions (RBAC) • Performance-tuned Laravel + Redis / Horizon • Legacy system modernization (PHP, JS) • Crypto payments & invoice automation • Mobile-friendly web apps (SPA/PWA) • Data scraping & document generation 𝗠𝗬 𝗣𝗥𝗘𝗙𝗘𝗥𝗥𝗘𝗗 𝗦𝗧𝗔𝗖𝗞 𝗙𝗢𝗥 𝗠𝗢𝗦𝗧 𝗧𝗬𝗣𝗘𝗦 𝗢𝗙 𝗣𝗥𝗢𝗝𝗘𝗖𝗧𝗦: • Backend / API: PHP 8.4, Composer, Laravel, "The Laravel Architect Badge" (Laracasts, june 2025) • Frontend: Blade + Livewire / Vue.js (3, Composition API) + Typescript + Pinia (state management) + Inertia.js, SPA, SSR • Styles: TailwindCSS + PrimeVue, SCSS, CSS3, HTML5, Flexbox, Vite • Mobile: Dart, Flutter (Android / iOS), Riverpod (state management) • Testing: TDD, Pest 4 (unit / feature), Dusk (browser) • DB: PostgreSQL / MySQL / MariaDB / SQLite • AI API: ChatGPT / DeepSeek • Web-server: Nginx + php-fpm / Laravel Octane + FrankenPHP • SEO Markup: Schema.org, JSON-LD, Opengraph • Money: Stripe / any bank systems • Cryptocurrency: NOWPayments / BitPay • Background Tasks: Cron / Supervisor / Systemd • Queues: Horizon + Redis / RabbitMQ / Kafka • Cache: Redis • API Docs: Swagger / OpenAPI • SSL: LetsEncrypt • Corporate Domain Mail: ZohoMail / Gmail • Full Text Search: Scout + MeiliSearch / Typesense (simple systems), OpenSearch (complex systems) • Transactional Mail Notifications: Brevo / ZeptoMail • Push Notifications: Firebase / Supabase • Maps: Mapbox / Google / Yandex / Leaflet / OpenStreetMap / Geocoding API • Analytics: Google Analytics / Yandex Metrika • Realtime Broadcasting: Laravel Echo, Laravel Reverb (simple systems), Soketi / OpenSwoole (complex systems) • CDN: Cloudflare, Fastly, Selectel, Akamai • API Development: GraphQL / REST, Swagger / OpenAPI, JSON / XML / SOAP • API Testing: Postman • Debug: Xdebug, Laradumps, Mailpit, Horizon, Telescope • I18n: Multi language support • Admin Panel & Data Management: Filament • Architecture: Entity–Service–Presenter (ESP)!!, DDD, MVC, DI, SOLID, GRASP, DRY, KISS • RBAC: Roles / Permissions • Browser Extensions: TypeScript, SCSS, Vite, Chrome / Brave • Hosting: DigitalOcean, Hetzner, VPS / VDS, Cloud Hosting, DNS Settings • OS: Ubuntu 24 • VCS: Git, GitLab (standalone), GitHub • Graphic Design Tools: Photoshop, Illustrator, Figma, Canva • Automation: Telegram Bots / Zapier • Notification Channels: Telegram API, Firebase, Email, SMS, Web Push API • Email Templates: Maizzle (TailwindCSS style) • Performance: Pulse 𝗔𝗗𝗗𝗜𝗧𝗜𝗢𝗡𝗔𝗟 𝗕𝗔𝗖𝗞𝗚𝗥𝗢𝗨𝗡𝗗 𝗔𝗡𝗗 𝗘𝗫𝗣𝗘𝗥𝗜𝗘𝗡𝗖𝗘: • API integration: ChatGPT, DeepSeek, Google, Yandex, 2GIS, VK, Klaviyo, Zoho, CloseCRM, Podio • Email Services: MailerSend, Mailgun, Google, Yandex • Backend Development: Yii2, Node.js, Express.js, Axios • Frontend Development: Bootstrap 3-5, JavaScript (ES6), jQuery, Pixi.js, Webpack, npm / bower / yarn • Databases: MySQL, SQL, Sphinx, Memcached, MongoDB, Firestore, Realtime Database, Neo4j • Data Scrapping: PHP (cURL, DOM Crawler), Regular Expressions, XPath, Selenium, Puppeteer, Proxies, Parallel Processes, CAPTCHA Bypass • SEO: Clean URLs, Canonical Tags, Optimized Routes, Robots.txt, Auto-Generated Sitemaps, Multilingual Support • Internalization: Web and mobile, any count of languages and locales • Real-time features: Socket.IO, AJAX, Firebase, WebRTC, WebSockets • Document automation: PHPWord, PHPOffice, LibreOffice, Tesseract OCR (text from image) • Security: Two-Factor Authentication, Google Authenticator, QR Codes, SMS If you're looking for a dedicated developer who combines technical excellence with business insight, feel free to reach out. Let's discuss how I can contribute to the success of your next project. Best regards, Alexander

Are you looking for a long-term partner rather than just another freelancer? I specialize in custom WordPress development and web design with a focus on in-depth research, problem-solving, and building sustainable systems for my clients. I don’t just deliver tasks – I work as part of your team, helping you understand what's not working, proposing practical solutions, and improving your product over time. Many of my clients stay with me for months or even years because they value my strategic thinking, attention to detail, and reliability. Since 2014 I have been creating websites and plugins using Wordpress, HTML5 / CSS3, JavaScript, PHP, MySQL, jQuery. Here are my skills: • Wordpress • Figma to Wordpress • Woocommerce • WPML / Polylang • Metabox / Visual Composer / WpBackery / Elementor / Gutenberg, etc. • HTML5 • CSS3 • jQuery, AJAX • PHP • MySQL • Bootstrap / Foundation / Popular Paid Themes for Wordpress • API: Google, WordPress REST API I’ve worked with a wide range of hosting environments including GoDaddy, SiteGround, Kinsta, Bluehost, and AWS Lightsail – so I know how to adapt to different infrastructures and solve issues quickly. There are a lot of developers who look for quick, easy money on the upwork, but I'm looking for a long-term cooperation, that's why I'm ready to work for you for the first hour absolutely free, it can be a test task or some small task on your current project Looking forward to working together.

Experienced backend Java developer with over a decade of expertise in developing and maintaining high-quality software solutions. My career includes roles at Accenture, Credit Suisse and GFT Group. Based in Poland, I have also worked in London with Luxoft and Unibet, a leading company in the gambling industry. Top-rated Upwork freelancer, ranked in the top 5% of performers with a 100% Job Success Score. Proficient in Java, Spring Boot, REST APIs, and cloud technologies (AWS). Adept at working with distributed international teams, emphasizing clean code practices and delivering challenging projects. Programming Languages: Java, JavaScript, Scala APIs & Integrations: RESTful APIs, GraphQL, WebSocket, RabbitMQ, JMS, Kafka Cloud & DevOps: AWS (Cloudformation), Docker, CI/CD (Jenkins, GitHub Actions) Frameworks & Tools: Spring Framework, Spring Boot, Hibernate, JPA Version Control: Git, GitLab, Bitbucket Databases: MySQL, PostgreSQL, MongoDB, Redis Testing: JUnit, Mockito, Cucumber, TDD Others: Observability, Keycloak, Angular, Maven, Bash

🚀 𝐓𝐡𝐞 𝐭𝐨𝐩 𝟏% of elite talent in Full-Stack Web Development & Tech Leadership 🏆 CTO at Onix-Systems | 25+ Years of Experience | Enterprise Solutions Architect & AI Product Pioneer ⚡ My goal is simple — transforming raw business ideas into highly profitable, production-ready, and market-leading digital products. 🙋‍♂️ Click Hire or Invite Senior Full Stack Developer & Full-Stack Web Development Expert 💻 WHAT YOU AND YOUR TEAM GET Senior Full Stack Developer & CTO - 25+ years of driving technology strategies, designing bulletproof system architectures, and leading senior engineering teams. Full-Stack Web Development Master's - high-performance web application development utilizing React, Node.js, and PHP to build scalable SaaS, FinTech, and Enterprise software. AI & Automation Systems Innovators - custom LLM applications, RAG pipelines, and intelligent workflow automations seamlessly integrated into your infrastructure. 📊 ACHIEVEMENTS IN NUMBERS (BUSINESS & SYSTEM IMPACT) 25+ years, 50,000+ engineering hours, 200+ successful launches delivered as a Senior Full Stack Developer and tech leader across global industries. Full-Stack Web Development for Enterprise & SaaS Platforms: Engineered and launched custom AI-powered SaaS platforms that scaled to millions of active users with 99.99% operational uptime. Accelerated product development cycles by 40% by deploying optimized React component libraries and agile workflows. Backend Architecture & API Engineering (Node.js & PHP): Reduced server infrastructure costs by 50% by migrating legacy monoliths into scalable microservices using Node.js, NestJS, and PHP. Optimized heavy data-processing pipelines, reducing database latency by 70% via tailored PostgreSQL, MongoDB, and MySQL schemas. AI App Development & Workflow Automation: Developed and integrated proprietary OpenAI GPT, Claude, and Gemini models into operational CRMs, increasing client workflow efficiency by 180%. Successfully deployed secure, HIPAA-compliant healthcare applications and high-security FinTech platforms with built-in Stripe / PayPal integrations. 🎯 WHERE WE DELIVER (CORE EXPERTISE) As a Full Stack Developer & Solution Architect: I handle the full cycle of Full-Stack Web Development, defining technical roadmaps, designing scalable web applications, and ensuring bulletproof cyber-security protocols. As a Front-End Development Expert: Crafting pixel-perfect, highly responsive user interfaces using React, Next.js, TypeScript, Vue.js, and Angular to ensure maximum conversion rates and premium UX. As a Back-End Development Authority: Designing ultra-fast APIs and core services with Node.js (Express/NestJS), PHP, Python (FastAPI/Django), and modern Serverless Stack architectures. As a Cloud & DevOps Engineer: Implementing enterprise-grade cloud deployments via AWS, Google Cloud, and Azure, utilizing Docker, Kubernetes, and automated CI/CD pipelines. 🛠 TECH STACK & ARCHITECTURE ECOSYSTEM Frontend Suite: React, Next.js, TypeScript, Tailwind CSS, Vue.js, Angular, Responsive Web Design. Backend Core: Node.js, NestJS, Express.js, PHP, Python, FastAPI, Django. Databases & Caching: PostgreSQL, MongoDB, MySQL, Redis. APIs & Global Integrations: REST APIs, GraphQL, Webhooks, Stripe, PayPal, Twilio, SendGrid. Cloud & DevOps Platform: AWS (Amazon Web Services), Google Cloud, Azure, Docker, Kubernetes, Jenkins, GitHub Actions CI/CD. 🧠 DEEP INDUSTRY EXPERIENCE AI & SaaS Startups: Rapid MVP development, RAG pipelines, AI chatbots, and predictive analytics tools. FinTech & E-commerce: High-load payment gateways, customized checkout solutions, compliance, and ledger systems. Healthcare & PropTech: Automated workflow systems, secure patient portals, CRM platforms, and real-time data visualization dashboards. Enterprise Automation: Heavy B2B platforms, marketplaces, and cross-platform integrations. ⚡ HOW WE WORK TOGETHER (THE CTO VALUE) Strategic Discovery: As a CTO, I align your business goals, success metrics, and timeline constraints before writing a single line of code. Architecture Blueprinting: We map out the core database schemas, React frontend components, and Node.js / PHP API flows to ensure long-term scalability. Agile Iteration: Backed by the senior engineering powerhouse at Onix-Systems, we deliver high-velocity sprints with predictable, production-ready releases every 2 weeks. DevOps & Launch: Secure deployment across AWS/GCP/Azure with ongoing tech partnership and proactive optimization based on product metrics. Looking for an elite Senior Full Stack Developer, CTO, and Full-Stack Web Development team to turn your complex concept into a world-class, scalable web platform? Let’s connect! Send over your project brief, scope, or existing codebase notes, and I’ll provide a high-level strategic roadmap for your next big launch. ☎️

💼 Senior Mobile & Full Stack Developer | iOS • Android • React Native • Flutter • AI Apps ✅ 22+ Years Experience ✅ 2000+ Projects Delivered 💰 $700K+ Earned on Upwork We help startups and businesses build modern, scalable, and high-performance mobile apps — from MVP to production. If you're looking for a Senior Mobile App Developer who can deliver a clean, fast, consumer-grade app with great UX — you're in the right place. 📱 Mobile App Development (iOS & Android) ✔ Native iOS (Swift, SwiftUI) ✔ Native Android (Kotlin, Java) ✔ Cross-platform (React Native, Flutter) ✔ MVP Development & rapid prototyping ✔ App Store & Google Play submission We build apps that are: Fast & responsive Scalable & production-ready Designed for real users (not just code) ⚙️ Full-Stack & Backend Development ✔ Node.js / Express / NestJS ✔ REST API & API Integration ✔ Firebase / Supabase / Firestore ✔ PostgreSQL / SQL / NoSQL ✔ AWS / Cloud infrastructure We handle the full flow: Mobile App → Backend → API → Cloud → Deployment 🤖 AI-Powered Applications ✔ AI integrations (OpenAI, Claude API) ✔ Image & Vision processing ✔ Audio transcription & processing ✔ Smart recommendations & automation Perfect for: AI mobile apps Smart assistants Data-driven products 🔑 Core Features We Build ✔ User Authentication (JWT, OAuth, Face ID) ✔ Push Notifications ✔ In-App Purchases & Subscriptions ✔ Camera & Image Processing ✔ GPS / Google Maps / Location services ✔ Real-time features & chat apps ✔ Payments (Stripe integration) 🎨 UX/UI & Product Focus We don’t just code — we build products users love: ✔ Clean, modern UI ✔ Pixel-perfect implementation (Figma → App) ✔ Smooth animations & micro-interactions ✔ Fast load time & performance optimization 🚀 Why Clients Choose Us ✔ Senior-level expertise (not junior outsourcing) ✔ Proven production apps (App Store & Google Play) ✔ Strong focus on UX & performance ✔ Experience with startups, SaaS & AI products ✔ Clear communication & fast delivery 📩 Let’s Build Your App We’re a great fit if you need: ✔ Mobile App Developer (iOS / Android / React Native / Flutter) ✔ MVP built fast and correctly ✔ AI-powered mobile application ✔ Scalable backend & API architecture ✔ Full-stack product development 📌 Send an invite — let’s discuss your app