Shopify developer for stores that require reliable theme customizations, integrations, and complex bug fixes – without disrupting checkout. I work safely in a duplicate theme, test on mobile and desktop, and provide clear handoff notes. My experience with Ruby on Rails, FastAPI, React, and APIs is useful when a Shopify request requires custom backend logic or automation—not just another app installation. I can help with: • Theme customization and custom Liquid sections • Custom app development and API integrations • Storefront bugs, search issues, and JavaScript fixes • Order, shipping, and app integrations • Custom Shopify functionality backed by 3rd-party APIs • Reliable ongoing technical support Send your store URL and the result you want. I'll tell you the safest practical path to implement it.

I’m a Senior AI Developer with 11+ years of hands-on experience in Machine Learning, Deep Learning, Natural Language Processing (NLP), Computer Vision, and Data Science, building intelligent systems that think, see, speak, and create like humans. Over the past decade, I’ve successfully delivered 70+ AI projects across startups, agencies, and enterprises - consistently improving performance, efficiency, and business outcomes with measurable impact. **Key Achievements & Results: - Increased model accuracy from 76% → 98.4% on large-scale prediction systems. - Reduced manual workloads by up to 90% through end-to-end AI automation. - Delivered AI pipelines processing over 1.5 TB of data daily with real-time insights. - Built AI chatbots handling 100K+ daily user interactions and improving engagement by 240%. - Created AI art and video generation platforms producing 250,000+ unique creative assets monthly, cutting production costs by 70%. - Developed computer vision solutions with YOLOv8 + PyTorch reaching 99.2% detection accuracy and <45ms response time. - Integrated predictive analytics models that boosted marketing ROI by 52% and sales forecasting accuracy by 33%. **Core Skills & Tech Stack: - AI & Machine Learning: Machine Learning, Deep Learning, Neural Networks, Artificial Intelligence - Frameworks & Tools: TensorFlow, PyTorch, Scikit-Learn, OpenCV, FastAPI, LangChain Programming: Python, JavaScript - Specialties: Natural Language Processing (NLP), Computer Vision, AI Chatbots, AI Art & Video Generation, Data Science, Predictive Analytics - Methodologies: Reinforcement Learning, Transfer Learning, Model Optimization, LLM Integration I have strong experience in Python, TensorFlow, PyTorch, NLP, and Computer Vision, and I’ve deployed production-grade AI systems that run across cloud platforms, handle millions of data points, and deliver real business value - not just prototypes. **Project Highlights: - AI Chatbot Platform: (OpenAI + LangChain + FastAPI) - scaled to over 120K+ users/day, reducing support response time by 80%. - AI Art & Video Generator: for a creative brand - automated visual production, generating 10K+ unique videos weekly and saving hundreds of man-hours per month. - Computer Vision App: YOLOv8 + PyTorch real-time detection system - processed 1.2M frames/day with 99% precision. - Data Science Engine: built a predictive analytics model that increased lead conversion by 41% and optimized ad spend by 28%. - NLP Pipeline: fine-tuned BERT-based models to process 10M+ text entries, achieving 98% sentiment accuracy. I’m passionate about Artificial Intelligence, Machine Learning, NLP, Deep Learning, and Computer Vision - creating AI systems that learn, adapt, and perform at scale. If you need someone who combines creative thinking, deep technical expertise, and business-driven AI strategy, I’m the one to turn your idea into a high-performance, scalable AI product. What’s the most ambitious AI project you’d like to bring to life next?

🚀 Anyone can generate basic code today. But AI cannot architect a scalable multi-tenant SaaS, design secure relational databases, debug complex full-stack TypeScript data pipelines, construct robust Node.js backend microservices, or rescue a failing cross-platform React Native product. That requires an experienced Full Stack Developer. Hi, I’m Volodya. I am a Full Stack Developer. I help startups, founders, and enterprise teams build highly scalable SaaS platforms, high-performance web applications, and robust mobile ecosystems from the ground up. With nearly 5 years of commercial engineering experience and a proven record of successfully delivering $14,000+ long-term enterprise contracts on Upwork, I don't just write disjointed frontend components or basic backend scripts. I architect end-to-end solutions using strict TypeScript that bridge the gap between seamless user interfaces and powerful, secure server environments capable of handling heavy production traffic. 🧠 My Full Stack Engineering Philosophy Developing a modern enterprise platform requires a holistic approach to system design. A well-architected frontend built entirely on Next.js ensures maximum SEO visibility and blistering load speeds, but it is only as strong as the backend that supports it. By designing custom API-first Node.js architectures or leveraging modern BaaS solutions, I ensure your business logic is secure, fast, and scalable. Furthermore, integrating a React Native mobile application alongside your web platform ensures you capture complete market coverage across iOS and Android with a unified codebase. I enforce strict TypeScript rules across the entire stack-from the Next.js client to the Node.js server and the React Native mobile build. By utilizing TypeScript to share data models and validation schemas end-to-end, my development speed increases drastically while runtime bugs drop to near zero before deployment. ⚙️ What I Bring to Your Project • End-to-End System Architecture: I design complete software ecosystems. From planning relational database schemas to routing complex Node.js REST/GraphQL APIs and consuming them via React/Next.js, I take full ownership of the product lifecycle. • Secure & Scalable Backends: I build business logic that handles heavy concurrency. Whether it is integrating third-party payment gateways (Stripe, PayPal), setting up WebSocket connections for real-time data, or managing authentication flows (JWT, OAuth), I ensure your backend is bulletproof. • Sub-Second Next.js Performance: I specialize in Next.js Server-Side Rendering (SSR) and advanced caching strategies to ensure your application passes Core Web Vitals and feels instantaneous to the user. • Zero-Bloat React & React Native Codebases: I strictly follow DRY and SOLID principles. I build UI systems utilizing robust TypeScript schemas so your codebase remains easy for your team to read, maintain, and scale globally. 🛠 My Core Stack • Frontend: React, Next.js (SSR/SSG), Tailwind CSS. • Mobile: React Native, Expo, Cross-Platform Architecture. • Backend & APIs: Node.js, Express/NestJS, RESTful API Design, GraphQL. • Databases & BaaS: PostgreSQL, MongoDB, Supabase, Firebase. • Type Safety: TypeScript (Strict mode configured end-to-end for full-stack environments). • State Management: React Query (for server state synchronization), Redux, Zustand. • DevOps & Cloud: Vercel (native Next.js cloud), AWS, Docker, CI/CD pipelines. Let’s build a Full Stack product that scales efficiently across web, mobile, and cloud environments. 👉 Send me an invite to discuss your upcoming platform, or book my 30-minute "Architecture & Codebase Audit" consultation right here on my profile to get immediate technical guidance on your React, React Native, Node.js, Next.js, or cloud architecture setup.

I am a Flutter App Developer with 5+ years of commercial experience building scalable, high-performance Mobile App solutions using Flutter and Firebase. As a Flutter App Developer, I specialize in delivering full-cycle Mobile App development - from MVP to production-ready applications used by thousands of users. My core expertise as a Flutter App Developer includes building complex Flutter applications with Firebase backend integration, real-time features, and scalable architecture. 💼 What I do as a Flutter App Developer As a Flutter App Developer, I build modern Mobile App products using Flutter combined with Firebase services. ✔ Cross-platform Mobile App development with Flutter ✔ Backend integration using Firebase (Auth, Firestore, FCM) ✔ Scalable architecture (Clean Architecture, BLoC, GetX) ✔ Real-time features (WebSockets, chat, live dashboards) ✔ API integration (REST API, GraphQL) ✔ CI/CD and deployment (App Store, Google Play) 🧠 Expertise As a Flutter App Developer, I have strong experience working with: Flutter for high-performance UI Firebase for backend infrastructure Mobile App architecture and scalability Clean Architecture and SOLID principles State management (BLoC, GetX, Riverpod) I build every Mobile App with a focus on performance, scalability, and long-term maintainability. 📱 Project Experience As a Flutter App Developer, I have worked on multiple real-world Mobile App projects: 📈 Results ✔ Delivered multiple production-ready Mobile App products ✔ Built scalable Flutter architectures for long-term growth ✔ Implemented real-time systems using Firebase ✔ Successfully published apps to App Store & Google Play 🤝 Why work with me? As a Flutter App Developer, I focus on: ✔ Clean and scalable Flutter code ✔ Reliable backend with Firebase ✔ Fast delivery of Mobile App MVPs ✔ Clear communication and structured workflow

👋 Hey everybody and welcome to my Upwork space! I’m a high skilled Full-Stack web developer with experience in creating top-notch progressive web applications using the MERN tech stack, so it's an easy choice for you. I’m strong in creating complex database (SQL, NoSQL) structures, implementing code in Java, JavaScript, React.js, Nuxt.js frameworks, jQuery library. Worked on server-side rendering app using Next.js, GraphQL/Apollo/Relay. Previously I worked in complex and high-scale projects developing entire UI, backend, widgets and frameworks from scratch. Also worked with serverless cloud services like AWS, Firebase, Supabase. Proficient in Google Cloud, AI integrations. Performance and quality are the most important aspects of great web applications, alongside code quality and in-time delivery, which I do in my work. You will get your source code in the Git or Bitbucket repository. Using the latest technologies and tools in coding I will strive to build you a great web application. Just send me an invitation and let's discuss the project🚀

I work best with founders and CTOs who want a senior engineer who can own the technical path, challenge weak assumptions, and ship production software without constant supervision. I reply quickly and keep you updated. I raise points early rather than surprise you later. You can always reach me. I deliver on my commitments. 🤝 How I work I use a modern AI development workflow that leverages advanced tools for code generation, refactoring, testing, and reviews. My approach is efficient without sacrificing quality. I rely on my experience and judgment, while automation handles repetitive tasks. ✔ No surprises – We get clear on the scope and what success looks like before a single line of code is written. ✔ Open communication – You’ll always know where things stand, with regular updates and early warnings if anything pops up. ✔ Easy to work with – Fast replies, direct answers, and no chasing me down. I make collaboration smooth. ✔ Modern workflow – I use the latest tools to move quickly and deliver quality, freeing up time to focus on what matters. ✔ Every change is reviewed – Nothing hits production without real testing and a second set of eyes. ✔ Clean handoffs – I write code & tests that are easy to follow, document the details, and make sure the next engineer can jump in without headaches. As a Full-Stack Engineer, I build SaaS platforms, B2B products, dashboards, admin panels, internal tools, desktop applications, and web apps. My products are reliable in production and built for growth, covering frontend, backend, and infrastructure. If your MVP needs to ship, your prototype is stuck, or your codebase is slowing the team, I take the product from architecture through launch. I own the build, the trade-offs, and the messy production details that determine whether software works. 🚀 What I do as a Full-Stack Engineer ✔ Full-stack web app development (React, Next.js, Node.js, NestJS) ✔ SaaS platform & B2B product development ✔ Electron desktop apps (macOS & Windows, code-signed & notarized) ✔ Chrome extension development (Manifest V3) ✔ Backend & API development (Node.js, Python, PostgreSQL, GraphQL, REST) ✔ MVP development & zero-to-one product builds ✔ AI feature integration (LLMs shipped to real users) ✔ AI apps launching ✔ Architecture, code review & technical strategy As a founding engineer, I work across the full product lifecycle: Architecture → Data Modeling → API Design & Backend implementation → Frontend Build → Desktop / Extension Packaging → Testing → CI/CD → Deployment & Scaling ⭐ Experience 10+ years building production software, 20+ products shipped, Top Rated Plus · 100% Job Success. I've worked as a full-stack engineer for SaaS startups, enterprise B2B platforms, and product teams in fintech, healthtech, logistics, and internal tooling. I own end-to-end delivery, not just closed tickets. 🧩 Full-Stack Engineering Services • SaaS Web App Development • Full-Stack Product Development (React + Node.js) • Electron Desktop App Development (windows, linux, mac) • Chrome Extension Development • Backend & API Development • Dashboard & Admin Panel Development • MVP Development for Startups • AI Feature Integration • Architecture & Technical Strategy • Code Review & Refactoring ⚙️ Stack React · Angular · Next.js · TypeScript · Node.js · NestJS · Python · PostgreSQL · GraphQL · REST · Electron · Chrome Extensions · AWS · Docker · CI/CD · AI-assisted development (Claude Code, Codex) Why clients hire me as a Full-Stack Developer: • 10+ years of full-stack engineering • Deep expertise in React/Next.js, Node.js, and Electron • Owns architecture through delivery - no hand-holding • Gives honest estimates and flags risks early • Cares about what ships and how they hold up If you want a founding full-stack engineer who can own your SaaS, web, or desktop product from architecture through launch, send me what you're building. I'll reply within 1 hour with honest, actionable technical feedback. Full-Stack Development · Founding Engineer · React Developer · Next.js · Node.js Developer · NestJS · Python · TypeScript · PostgreSQL · GraphQL · REST API · MVP Development · SaaS Development · Electron.js · Desktop Application Development · Cross-Platform Applications · Code Signing · Apple Notarization · Chrome Extension · AI Integration · AWS · Docker · CI/CD · Angular · API · Frontend Developer

Most developers deliver code. As a Top Rated Plus Full Stack Developer, Mobile App Developer, and SaaS Developer with a 100% Job Success Score on Upwork, I deliver systems - ones that teams can confidently run, scale, and build on. Whether it is Mobile App Development, SaaS Development, or a full stack web product, I stay accountable for it long after the first release. Specialized in Full Stack Development and Mobile App Development with a strong focus on React Native, Flutter, Python, and SaaS Development architecture. As an experienced Full Stack Developer and Mobile App Developer focused on cross-platform iOS and Android apps and SaaS platforms, I work across the entire stack - from React Native and Flutter mobile apps to Python, Node.js, and Laravel backends. With a strong background in SaaS Development, backend API design, and mobile-connected platforms, I bring a backend-first mindset and deep attention to scalability and long-term maintainability. Proficient in React Native, Flutter, Python, Node.js, AWS, and Microsoft Azure as a Software Developer and Senior Web Developer. Core Specializations Full Stack Mobile App Development As a Full Stack Mobile App Developer and React Native Developer, I deliver cross-platform iOS and Android applications that perform like native products. As a Flutter Developer and Flutter Mobile App Development specialist, I build unified experiences where a shared codebase does not mean compromising quality. As a Mobile App Developer covering mobile app design, mobile app development, and full deployment lifecycle, I treat performance and reliability as non-negotiable from day one - not afterthoughts. Full Stack Web & React Development As a React Developer and Full Stack Developer, I build end-to-end web solutions using React, Vue, Next.js, and TypeScript on the frontend. As a Web Developer handling both Web Design and component architecture, I create scalable, maintainable interfaces backed by Python (FastAPI, Django, Flask), Node.js, and Laravel. As a Full Stack Developer with React and Node.js expertise, I own delivery from database schema to deployed product - clean API contracts, proper state management, and optimized data flow across every layer. SaaS Development & Backend Architecture As a SaaS Developer, I design and build SaaS Development platforms from MVP to mature multi-tenant products - including subscription logic, role-based access, and SaaS business development-ready architecture. As a Python Full Stack Developer and Backend Developer, I build robust APIs with Node.js and Python for high concurrency workloads. As a Full Stack Developer PHP specialist, I support Laravel and PHP-based ecosystems when projects require it. As a DevOps-minded engineer and React Native Developer, I manage infrastructure as code across AWS and Microsoft Azure environments. AI Integration & Cloud Infrastructure As a Full Stack Developer focused on AI Integration, I connect web and mobile frontends to AI-powered backends - implementing smart search, real-time suggestions, and LLM-driven features using OpenAI API and LangChain. As an AWS Architect with expertise in AWS (Lambda, S3, DynamoDB), Microsoft Azure, and Azure DevOps, I ensure data handling is high-speed, cost-effective, and secure across Web, iOS, and Android platforms. As a React Web Development and API Integration specialist, I build the connective layer that makes AI functionality feel responsive and production-ready. Clients typically work with me when they need: - Full Stack Developer to own frontend and backend - Mobile App Developer for React Native, Flutter, and native iOS/Android - SaaS Developer for SaaS Development platforms built to scale - React Developer or React Native Developer for web and mobile projects - Python Full Stack Developer or Backend Developer for API-driven systems - Senior Web Developer or Front End Developer with full stack depth - AI Integration and API Integration for new or existing platforms - AWS Architect or Azure-based cloud infrastructure and DevOps pipelines Technical Expertise - Mobile: React Native, Flutter, Swift, Kotlin, TypeScript, Redux Toolkit, React Query - Frontend: React, Vue, Next.js, TypeScript, Tailwind CSS - Backend: Python (FastAPI, Django, Flask), Node.js, Laravel, PHP, REST & GraphQL - AI & Automation: OpenAI API, LangChain, Vector Databases, RAG, AI Machine Learning - Data & Cloud: AWS (S3, Lambda, DynamoDB), Microsoft Azure, PostgreSQL, Redis - Tools: Docker, CI/CD, Git, Stripe, DevOps pipelines I do not take on Wordpress developer projects, SaaS marketing, Google Ads, or Digital Marketing. If you need to build a product from scratch, ship an MVP, or scale an existing SaaS Development platform - as a Full Stack Developer and Mobile App Developer, let us discuss your project.

Want to actually make money from your game and turn your idea into something that brings real value, not just another app that gets ignored? That’s exactly what this is about! Games built here consistently reach 100K+ to 500K+ downloads and generate real revenue for clients, because the focus is not just on development, but on gameplay, retention, and monetization from day one. Most games technically “work” but fail at gameplay, player experience, and long-term engagement. The focus here is simple, not just mobile game development or video game development, but building a game that people enjoy playing and keep coming back to. Everything starts with how the game feels. Before scaling, the core gameplay is shaped - how players interact with the game - how levels are structured - how progression works - and why someone would continue playing after the first session Once that is clear, the game is built in Unity with a strong balance between game design and game development, making sure mechanics, UI/UX, animation, and overall flow work together as one system. From there, the focus shifts to what actually drives growth - performance across Android and iOS devices - smooth gameplay and responsiveness - and systems like rewards, leaderboards, and monetization that support long-term engagement This naturally includes working with Unity, C#, mobile game systems, gameplay mechanics, 2D and 3D environments, animation, UI/UX, and optimization, but always with the goal of building a complete product, not just features. Because in the end - a successful game is not just about launching it’s about - players staying - coming back - and spending time (and money) inside the game If you want to build a game that actually performs - message me, and let’s turn your idea into a real money making machine!

E-commerce, marketplace, and SaaS platforms that drive real growth. 🏆 100,000+ active users reached on a single platform within 6 months 📈 20%+ conversion growth through data-driven UI decisions 💰 €10M+ annual revenue supported across e-commerce platform 🚀 Figma design → production-ready frontend in days, not weeks Senior Front-End Developer and Full Stack Developer with 7+ years of hands-on experience building products from the first commit to full production scale. I work primarily as a React Developer and Next.js Developer, crafting fast, SEO-friendly, and accessible interfaces with React.js, Next.js, TypeScript, and Redux. On the backend side, I connect everything using Node.js, Express.js, NestJS, and Firebase. My focus is always the same: a product that works, performs, and grows. 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐬 𝐈'𝐯𝐞 𝐛𝐮𝐢𝐥𝐭: European E-commerce Platform - Clothing Multi-store. Senior Front-End Developer on one of Europe's largest streetwear stores with €10M+ annual revenue. Built multi-store, multi-language, multi-currency architecture with full catalog management, promotions engine, and logistics integrations. Helped scale the platform into new European markets and establish it as the #1 streetwear destination online. Healthcare Marketplace - React Developer on a platform connecting clients with licensed psychologists for online therapy. Built therapist matching, session booking, wallet system, promo codes, and gift certificates. Result: 100,000+ active users within 6 months, consistently praised for UX quality. Travel Marketplace - Full Stack Developer and React Native Developer on a web and mobile app connecting charter pilots with travelers across US–Bahamas routes. Delivered split payments, Smart Check-In, passenger invitations, and scheduling system. Opened new revenue streams for pilots, streamlined the entire booking experience. E-commerce Platform - As a React Developer and Node.js Developer, I built a full-featured furniture store with advanced catalog filtering, product customization, wishlist, and comparison. Developed a custom CMS and CRM for independent business operations. Integrated AI-powered product recommendations and technical SEO, resulting in top search rankings. Result: 100,000+ monthly users 𝐂𝐨𝐫𝐞 𝐄𝐱𝐩𝐞𝐫𝐭𝐢𝐬𝐞: React.js and Next.js frontend development TypeScript, Redux, and state architecture React Native mobile development (iOS & Android) Full stack development with Node.js, NestJS, Express.js SaaS MVP → production delivery E-commerce and marketplace platforms (B2B / B2C / P2P) Figma to React conversion, pixel-perfect implementation Payment integrations (Stripe, PayPal) AI-powered features (OpenAI, GPT-4, automation) Performance optimization and Core Web Vitals REST API and third-party service integrations Firebase, MongoDB, real-time systems 𝐓𝐞𝐜𝐡 𝐬𝐭𝐚𝐜𝐤: Frontend: React.js, Next.js, TypeScript, JavaScript, Redux Mobile: React Native, Expo Backend: Node.js, Express.js, NestJS Database: MongoDB, Firebase, PostgreSQL Styling: Tailwind CSS, Material UI, Styled-components, Bootstrap, HTML5, CSS3 Tools: Git, CI/CD, Webpack, Vite Integrations: Stripe, PayPal, OpenAI, GPT-4, REST APIs, GraphQL Design: Figma, Zeplin, Adobe Photoshop, Illustrator 𝐖𝐡𝐲 𝐡𝐢𝐫𝐞 𝐦𝐞: ✔ Pixel-perfect implementation from any Figma file ✔ SEO-optimized, fast-loading Next.js applications ✔ Clean, maintainable component architecture built to scale ✔ Real-time features, complex API integrations, payment flows ✔ Daily updates, honest timelines, zero surprises ✔ Fluent English - comfortable across US and EU time zones 𝐈'𝐯𝐞 𝐰𝐨𝐫𝐤𝐞𝐝 𝐚𝐜𝐫𝐨𝐬𝐬 𝐫𝐨𝐥𝐞𝐬: React, React Developer, Frontend React Developer, Front-End, Next.js Developer, Full Stack Developer, Marketplace, E-commerce, React Native, React Node, React Native Developer, Mobile Developer, Web App Developer, Mobile App Developer, WordPress, Tailwind, Web Developer, SaaS Developer, E-commerce Developer, Nurpais, Marketplace Developer, AI Frontend Developer. Have a project in mind? Reach out - I'll respond quickly with the right questions to turn your idea into reality.

Highly accomplished Software Architect and Machine Learning Engineer with a solid mathematical background and 20+ years of experience. I specialize in bridging the gap between complex algorithmic research and high-performance system execution. My unique expertise combines advanced AI/ML development with a deep background in compiler design, domain-specific languages (DSLs), and low-level code optimization. Whether you need to develop production-grade ML models, optimize heavy computing algorithms, or build specialized software tools and custom IDEs, I deliver mathematically sound and architecturally robust solutions. 🧠 Core Expertise Machine Learning & Research: Algorithm development, statistical data processing, predictive modeling, and AI logic orchestration. Strong scientific and analytical background with proven experience in research and academic article writing. Compilers & DSL Engineering: Expert in the theory of formal languages, syntax analysis, parsers, and custom compilers. Prototyping and implementing Domain-Specific Languages (DSLs) tailored for specific business or technical domains. High-Performance & Optimization: Optimization of complex calculations, data structures, and database architectures for high-throughput systems. Full-Cycle Infrastructure: Designing client-server systems for massive data storage, visualization of observation results, and custom developer tools (Eclipse RCP/Xtext/Plugin development). TECHNICAL SKILLS SUMMARY 🤖 Machine Learning & Mathematics Algorithms & Math: Advanced Mathematics, Algorithm Design & Optimization, Statistical Analysis, Data Visualization. AI Logic: Neural Network integration, Data Processing pipelines, Game AI & Logic engines. Research: Scientific research, Data insights, Technical writing, and Academic publication standards. 🛠️ Compiler & DSL Development Formal Languages: Syntax Analysis, Parser Generation, AST Manipulation. Tools & Frameworks: Xtext, Xtend, ANTLR. IDE Development: Eclipse RCP, SWT/JFace, Custom Plugin Development. ☕ Enterprise Java & Backend Infrastructure Core Java: Java SE (High Performance), Java Reflection, Sockets/Networking. Frameworks: Spring (Core, MVC, AOP), Hibernate, JDBC. Data Processing: SAX, DOM, XSLT, Jasper Reports. Databases: PostgreSQL, MySQL. 📱 Legacy & Specialized Experience Desktop/Web UI: Swing, GWT, GXT. Cross-Platform & Graphics: LibGDX (Game engines/logic). Legacy Stack (ActionScript/Flex): Flex 4.6, ActionScript 3.0, Adobe AIR, Flash Media Server, PureMVC (valuable for legacy system migration). ⚙️ Tools & Workflow IDEs: IntelliJ IDEA, Eclipse. Build & Version Control: Maven, GIT, SVN. Architecture: Gang of Four (GoF) Design Patterns, Clean Architecture.