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Bohdan K.
$40/hr
100% Job Success
$100K+ earned
Available now
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Backend and full stack systems that handle real money, real transactions, and real scale. 🏦 $6.8M seed funding raised by a product built on my backend infrastructure 🔗 15+ projects shipped on Upwork ⚙️ 7+ years building APIs, payment flows, and Web3 integrations 🚀 From architecture to production - clean, maintainable, built to last Senior Backend and Full Stack Developer specializing in FinTech infrastructure, blockchain integrations, and scalable API systems. I work with startups and established teams that need backend done right: payment flows, crypto wallets, KYC/AML pipelines, DeFi protocols, and high-load REST and GraphQL APIs. My core stack is Node.js, Express, and NestJS. I've shipped production systems handling real financial transactions across Stripe, ACH, Apple Pay, Google Pay, Fireblocks, Coinbase API, and Bridge.xyz. On the blockchain side: Solidity, Ethers.js, Web3.js, Polygon, Ethereum, Solana, Gnosis Safe, and Moralis. I also cover the full stack with React, Next.js, and TypeScript - no handoff gaps, faster delivery. 𝐏𝐫𝐨𝐝𝐮𝐜𝐭𝐬 𝐈'𝐯𝐞 𝐛𝐮𝐢𝐥𝐭: Blockchain FinTech Platform - a Spanish blockchain-first fintech platform for crypto and fiat asset management that raised $6.8M in seed funding. Built backend infrastructure for multi-wallet management, crypto tax calculation, team collaboration features, and crypto-friendly banking integration. Stack: NestJS, Moralis, WalletConnect, Web3React, Snapshot. Debt Collection & Payments Platform - a debt collection platform with comprehensive payment infrastructure. Integrated Stripe, ACH, Apple Pay, Google Pay, Buy Now Pay Later, and partial payment flows. Connected Salesforce CRM, QuickBooks, and Xero. Built data visualization dashboards with Recharts for real-time financial reporting. DeFi Prime Brokerage - service built on Solana, powered by Serum's on-chain order book infrastructure. Responsible for API architecture, blockchain integration, and frontend connectivity. 𝐂𝐨𝐫𝐞 𝐄𝐱𝐩𝐞𝐫𝐭𝐢𝐬𝐞: - Scalable REST and GraphQL APIs with Node.js, Express, NestJS - Blockchain integrations: Ethereum, Polygon, Solana, smart contracts - Crypto wallet infrastructure: Fireblocks, Coinbase API, Gnosis Safe, Moralis - Payment systems: Stripe, ACH, Apple Pay, Google Pay, BNPL, crypto-fiat - KYC/KYB flows: Sumsub, identity verification pipelines - AML compliance: Elliptic, transaction monitoring - DeFi protocols, DEX integrations, dApp backends - FinTech infrastructure: Bridge.xyz, Rain.xyz, Kraken API - Database architecture: MongoDB, PostgreSQL, Supabase, Firebase - Cloud infrastructure: AWS, Azure, Google Cloud, CI/CD pipelines - Full stack coverage: React, Next.js, TypeScript 𝐓𝐞𝐜𝐡 𝐬𝐭𝐚𝐜𝐤: - Backend: Node.js, Express.js, NestJS, REST API, GraphQL - Frontend: React.js, Next.js, TypeScript, Tailwind CSS - Blockchain: Solidity, Ethers.js, Web3.js, Polygon, Ethereum, Solana FinTech: Fireblocks, Coinbase API, Kraken, Gnosis Safe, Bridge.xyz, Rain.xyz, Moralis, Elliptic, Sumsub - Payments: Stripe, ACH, Apple Pay, Google Pay, BNPL Databases: MongoDB, PostgreSQL, Supabase, Firebase - Infrastructure: AWS, Azure, Google Cloud, CI/CD, Docker I've worked across roles: Senior Backend Developer, Full Stack Developer, Web Developer, Node.js Developer, NestJS Developer, Express Developer, Blockchain Developer, Web3 Developer, DeFi Developer, FinTech Developer, Full Stack Developer React Node, API Developer, Crypto Wallet Developer, Payment Integration Developer, Backend Architect. The backend is where products either scale or break. Let's make sure yours scales. Message me, and we’ll review your project together.
Bohdan K. has worked .
Stubbs  🏆 Top rated plus React agency
Associated with
Stubbs  🏆 Top rated plus React agency
$1M+
earned
Zorian F.
$30/hr
100% Job Success
$100K+ earned
Available now
Offers consultations
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🔸 Mobile App Developer & CTO trusted by businesses to deliver products that survive production 🔸 10+ years of hands-on execution building scalable, high-performance mobile applications used by real users, not demos. I step in when quality, architecture, and long-term growth are needed. 🔸 100+ digital products launched 🔸 100% Job Success on Upwork 🔸 I am a CTO and hands-on mobile app developer leading ORIL, a senior engineering team focused on delivering high-performance, secure, and scalable mobile solutions. If you are looking for a reliable mobile developer or an experienced react native developer, you are working with a team that understands production, performance, and long-term growth. Our Core Strength: Mobile App Development We specialize in Mobile App Development for iOS and Android, with deep expertise in react native to deliver efficient cross-platform solutions without compromising native performance or user experience. As a mobile app developer team, we build production-ready applications used by real users on real devices, not prototypes or proof-of-concepts. Every mobile developer on our team has shipped apps to the App Store and Google Play. Every react native developer understands how to balance cross-platform efficiency with native quality. I also collaborate with teams as a Mobile App Developer and React Native Developer, ensuring that mobile designs are implemented efficiently and accurately. Working alongside mobile developer engineers this collaboration guarantees that every mobile product performs reliably on iOS and Android, meets user expectations, and is production-ready. What we deliver: 🔸 React Native App Development for iOS & Android 🔸 Native iOS Development and Kotlin-based Android apps 🔸 Cross-platform and native solutions led by senior engineers 🔸 Backend for mobile apps: Node.js, Java, secure and scalable APIs 🔸 AI-powered features and chatbots for mobile products Our Team & Approach Our team delivers end-to-end mobile solutions combining native iOS development, Kotlin-based Android apps, and cross-platform architectures. Every project is guided by a strong full stack developer mindset, ensuring the mobile application, backend services, and integrations operate as a single, reliable system. The team includes senior android developer specialists who optimize native features, iOS engineers who ensure App Store quality, and experienced react native developer experts who deliver cross-platform efficiency. When project scope requires broader technical coverage, we bring in flutter developer specialists for alternative cross-platform needs, web developer experts for admin dashboards and landing pages, or python developer professionals for backend systems, data processing, and AI integrations. Why Choose a Mobile App Developer with Production Experience As a mobile app developer with over a decade of experience, I've seen what separates successful launches from failed ones. The difference isn't just technical skill, it's understanding production constraints, user behavior, battery optimization, App Store guidelines, and long-term maintenance. Whether you need a mobile developer to rescue a struggling project, a react native developer to build from scratch, an android developer to optimize performance, a full stack developer to connect mobile with backend systems, or a web developer to build companion dashboards—I bring both strategic oversight and hands-on execution to ensure your product thrives in the real world. Industries we work with: FinTech, Finance & Banking, Healthcare, HealthTech, Real Estate, Property Management, Marketplaces, Logistics, Transportation, Automotive, Retail, Media, Education, Fitness, Travel, Hospitality, Construction, and more. If you need a mobile app developer, a trusted mobile developer, or a full team led by an experienced react native developer to build fast, scalable, and production-ready mobile applications, let’s connect and discuss how to turn your idea into a successful product. 🔸 Let's Build Your Mobile Product! 🔸
Zorian F. has worked .
ORIL
Associated with
ORIL
$1M+
earned
Dmytro M.
$40/hr
100% Job Success
$30K+ earned
Available now
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⭐️ Top Rated Plus — Top 3% of talent on Upwork ✅ 11+ years of professional experience ✅ 40+ projects successfully delivered 📈 Boosted client productivity by up to 70%, supporting platforms with 100k+ users ⚡ Improved application loading speed by 30–50% ✅ $50M+ in client revenue supported through the platforms I’ve built ✅ 90%+ repeat client rate I’m a Full Stack Developer, Web Developer, and React Developer with more than 11 years of hands-on experience building scalable, high-performance web and mobile applications. My core strength lies in Node.js backend engineering combined with React / React.js frontend development, allowing me to deliver complete, production-ready systems from database to UI. As a Full Stack Developer, I work across the entire application lifecycle — from backend logic and APIs to frontend interfaces and performance optimization. As a Web Developer, I focus on reliability, maintainability, and long-term scalability. As a React Developer, I build fast, interactive user interfaces that feel smooth and intuitive across devices. I work with startups and companies building AI-driven SaaS platforms, AI automation systems, conversational assistants, and internal AI tools. 🔧️ CORE TECHNICAL EXPERTISE 📌 AI Integration & AI Agent Development — OpenAI / LLM / Conversational AI As an AI Developer and Full Stack Developer, I design and implement AI-powered systems using modern LLM technologies and AI APIs. My work includes AI agent architectures, conversational AI systems, AI copilots, and AI workflow automation. I integrate platforms like OpenAI, GPT, Claude, and other LLM providers into SaaS products and internal tools. This includes RAG pipelines, knowledge base ingestion, tool-calling agents, AI assistants, and AI automation workflows. I also build real-time AI systems, including voice AI applications using streaming APIs, speech-to-text (ASR), and text-to-speech (TTS). 📌 Backend Development — Node.js / TypeScript / API Architecture As a Backend Developer and Full Stack Developer, I design scalable server-side systems using Node.js, TypeScript, Nest.js, and Express.js. As a Full Stack Developer and Web Developer, I design and implement server-side systems using Node.js, building REST and GraphQL APIs, background jobs, and service-based architectures. My experience includes authentication flows, authorization layers, data validation, logging, error handling, and API versioning — all written with clarity and long-term support in mind. I focus on building clean, maintainable backend architectures that support long-term product growth. 📌 Frontend Development — React / Next.js / Modern Web Applications As a React Developer and Full Stack Developer, I build modern user interfaces and SaaS platforms using React, Next.js, TypeScript, and Tailwind. As a React Developer and Web Developer, I create single-page applications and complex dashboards using React. I focus on clean component structure, predictable state management, responsive layouts, and performance-conscious rendering. My React work supports both web platforms and mobile-focused interfaces. I design frontend systems that integrate seamlessly with AI services, APIs, and backend platforms. 📌 Database Architecture — PostgreSQL / Supabase / MongoDB / Redis Experienced Full Stack Developer working with modern database systems including PostgreSQL, MySQL, MongoDB, Supabase, and Redis. Experienced Full Stack Developer working with PostgreSQL, MySQL, and MongoDB, including schema design, indexing strategies, query optimization, and data migration. I ensure backend systems remain efficient under growth and high traffic. I ensure backend systems remain stable and scalable under high traffic and growing data volumes. 📌 Cloud & Infrastructure — AWS / Docker / Cloud Platforms As a Full Stack Developer and AI Integration Engineer, I deploy and maintain applications in cloud environments. As a Web Developer and Full Stack Developer, I deploy and maintain applications on AWS, using services such as EC2, ECS, S3, CloudFront, and CI/CD pipelines. I manage environments, automate deployments, and ensure applications scale reliably. My goal is to build reliable infrastructure that supports production AI applications and SaaS platforms. 📌 API & Platform Integrations I develop and integrate REST APIs, external services, and automation platforms using Node.js. I build and integrate RESTful and GraphQL APIs using Node js, connecting payment gateways, OAuth 2.0 providers, external services, and internal systems. These APIs are consumed by React applications and mobile interfaces built by me as a React Developer and Web Developer. 💥 WHAT I CAN DO FOR YOU ✅ Build AI-powered applications and AI agents ✅ Integrate OpenAI / GPT / Claude APIs into SaaS platforms ✅ Develop scalable Node.js backend services ✅ Build modern React / Next.js applications ✅ Implement RAG pipelines and AI knowledge systems ✅ Design full-stack SaaS architecture
Seedium
Associated with
Seedium
$2M+
earned
Dmytro P.
$45/hr
100% Job Success
$600K+ earned
Available now
Offers consultations
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I specialize in WordPress Website Development and Custom WordPress Development & Design for businesses that need a fast, scalable, and conversion-focused WordPress Website. My work combines WordPress Website Design, Custom WordPress Website Development, Website Development, performance optimization, SEO structure, and clean content management. I don’t just build pages. I help turn a WordPress Website into a working business asset that generates leads, sales, and long-term value. More power with 'My ideal flow'™: Idea → Discovery → Prototype → Design → Development → Testing → Launch → Support. 12+ Years on Upwork $600K+ Total Earnings 200+ Satisfied Clients 80+ Jobs Completed 100% Job Success Score Top Rated Plus Freelancer “Dmitry is always solution orientated and a clear communicator. He is committed to the quality of the project and is very detail oriented. He is always held accountable for outcomes.” Client review For most clients, WordPress Website Development is not just about building pages. Good WordPress Website Development should include structure, speed, usability, SEO basics, and easy content management. My approach to WordPress Website Development is practical: first I understand the business goal, then I plan the content structure, then I handle design, development, testing, launch, and support. That is why my WordPress Website Development process often includes Custom WordPress Development, WordPress Website Design, Website Redesign, WooCommerce, Elementor, ACF, and performance optimization. I am a WordPress Developer, WordPress Website Expert, and Web Developer focused on Custom WordPress Development, WordPress Website Design, WordPress Elementor, WooCommerce, Website Redesign, Website Customization, WordPress Website Optimization, and WordPress SEO. Typical work includes: WordPress Website Development Custom WordPress Website Development Custom WordPress Development WordPress Website Design WordPress Design WordPress Elementor development WooCommerce and Ecommerce Website development Website Redesign Website Customization WordPress Website Optimization WordPress SEO structure ACF, flexible content, and custom admin systems Custom themes and WordPress Theme development WordPress Plugin customization API integrations with CRMs, marketing tools, payment systems, and automation platforms Front-End Development with HTML, CSS, JavaScript, and PHP Most of my projects go beyond standard brochure sites. Clients usually come to me when their current WordPress Website is slow, hard to manage, difficult to scale, or not converting visitors into leads and customers. Some projects require Custom WordPress Development with ACF, Options Pages, flexible content blocks, structured page systems, custom post types, and clean admin logic. Others need WooCommerce functionality, subscriptions, custom checkout flows, payment logic, product structures, or integrations with third-party platforms. From the design side, I focus on WordPress Website Design that supports real business goals: clear user flow, strong content hierarchy, responsive layouts, conversion-focused sections, and SEO-friendly structure. I also work on Website Redesign projects where the existing site already has traffic, but the design, performance, structure, or user experience is holding it back. In those cases, I rebuild the WordPress Website with better UX, better speed, better SEO structure, and easier content management. A large part of my work is built with WordPress Elementor when clients need speed, flexibility, and easy editing. For more complex projects, I use Custom WordPress Development instead of relying only on builders. My projects often include: Custom WooCommerce functionality Performance optimization and Core Web Vitals Large or complex WordPress Websites Multi-language and multi-site structures Advanced ACF usage Gutenberg and custom blocks API integrations Plugin conflict debugging Server-level and database-level issue solving Responsive Front-End Development At the core, every project combines three things: WordPress Website Development, WordPress Website Design, Custom WordPress Development. Not as separate services, but as one system that impacts revenue, user behavior, speed, search visibility, and long-term scalability. I work as a WordPress Developer and WordPress Designer for WordPress Website, WordPress Development, Elementor, WooCommerce, SEO, Website Design, Web Development, and conversion-focused builds. If you are looking for a WordPress Website Developer, WordPress Development Expert, Web Developer, or Website Design partner who can handle both design and development, I can help you plan, build, optimize, and support your WordPress Website from idea to launch. Wordpress Elementor custom dev
Dmytro P. has worked .
Hutko | Wordpress Developer, Wordpress Designer, SEO, Custom Development | React, Laravel, Shopify, Webflow, Vue, Angular, Next
Associated with
Hutko | Wordpress Developer, Wordpress Designer, SEO, Custom Development | React, Laravel, Shopify, Webflow, Vue, Angular, Next
$1M+
earned
Oleksandr P.
$35/hr
100% Job Success
$100K+ earned
Available now
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Need a mobile app built that holds up after launch? I lead mobile app development that ships production-ready iOS and Android apps that survive real users - several are live on the App Store and Google Play right now. I'm Oleksandr, founder and lead engineer at Kultrix, an AI and Mobile App Studio, working from Lviv. Most of our work is React Native mobile app development, plus the AI features and backend that make an app actually useful. I run engagements as a long-term technical partner, not a vendor you chase for updates - which is why several engagements have run 16 months to 4+ years. You get senior engineering ownership from first call to store release: clear scope, milestone-based delivery, honest timelines, and a lead who is accountable for the result. As founder and lead engineer, I make sure the mobile app development gets done right, not just fast. WHAT WE BUILD - Full mobile app development in React Native and Expo, from idea to store release - a cross-platform iOS and Android app from one codebase, typically a launched MVP in 6-10 weeks. With a senior React Native developer leading, we cover MVP development, App Store and Google Play submission, and everything in between. - AI integration inside mobile apps - chat, image and vision analysis, and conversational voice (OpenAI and Anthropic Claude), already shipped in live AI mobile apps. Clean API integration so the AI feature feels native, not bolted on. - Rescue and refactor of React Native apps that broke under real users - performance, crashes, and stability work to get an existing app back to store-ready. - Backend when your app needs more than screens: Node.js, NestJS, Python and FastAPI, PostgreSQL, MongoDB, Firebase, and Supabase (including auth and RLS). WHO IT IS FOR - Starting from scratch: a clear path from idea to a launched MVP in 6-10 weeks, built by a team that has shipped to both stores. - Already have an app: mobile app development help with new features, performance, and stability - whether you need an iOS developer, an Android developer, or both. - Want to add AI: a chat, vision, or voice feature shipped into your live cross-platform app through careful AI integration, scoped so it ships fast and stays maintainable. HOW WE WORK You talk to the people building your app, not a sales layer. We agree on scope and milestones up front, you see working builds early and often on TestFlight and internal tracks, and you get honest status instead of silence. When something is harder than estimated, you hear it early - with options, not surprises. The goal is a stable app you can grow on, and a codebase your next mobile app developer can read without a rewrite. VERTICALS WE KNOW We have shipped mobile app development work across health and wellness, nutrition, and fitness (calorie tracking, meal analysis, AI coaching), fintech and Web3 (payments, Plaid, Polygon on-chain apps), SaaS (Stripe billing and dashboards), and internal tools and logistics (warehouse and operations systems). If your app lives in one of these spaces, we have built and launched something close to it. RESULTS - An AI nutrition tracker - React Native meal and calorie analysis with Anthropic Claude and OpenAI - live on both the App Store and Google Play, owned end to end (mobile, API, and admin). - An AI fitness app on a Python and FastAPI backend with OpenAI, live on the App Store and Google Play. - A conversational-voice health app built with React Native, Expo, and Claude. - A Web3 scratch-card app on Polygon with Plaid integration, live on Google Play, plus a daily-quotes app on the App Store. - A warehouse operations system that runs 4x faster for 100+ employees. - Long-term mobile app development engagements kept for 16+ months and 4+ years - the clearest signal that this work lasts. OUR STACK React Native, Expo, TypeScript for cross-platform iOS and Android; Node.js, NestJS, Python and FastAPI, PostgreSQL, MongoDB, Firebase, and Supabase on the backend; Stripe, in-app purchases, push notifications, and WebSockets for real product features; and AI APIs (OpenAI and Anthropic Claude) for chat, vision, and voice. This is the full toolkit for modern mobile app development and AI integration, from first commit to a stable app on the App Store and Google Play. Send me your idea or your existing app and you will get back a clear, honest breakdown - what to build first, what can wait, and a realistic timeline for the mobile app development. No pressure, no jargon, just a straight answer from the lead who would own the work. Oleksandr - founder and lead engineer, Kultrix (AI and Mobile App Studio).
Oleksandr P. has worked .
Kultrix - AI & Mobile App Development Studio - React Native iOS Android
Associated with
Kultrix - AI & Mobile App Development Studio - React Native iOS Android
$80K+
earned
$50/hr
100% Job Success
$40K+ earned
Offers consultations
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🥇 𝗧𝗢𝗣 𝟭𝟬% 𝗪𝗲𝗯𝗗𝗲𝘃 🕒 𝟮𝟭𝟬𝟬+ 𝗛𝗼𝘂𝗿𝘀 𝗼𝗻 𝗨𝗽𝘄𝗼𝗿𝗸 ✅ 𝟭𝟬+ 𝗬𝗲𝗮𝗿𝘀 𝗼𝗳 𝗲𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 𝗶𝗻 𝗪𝗼𝗿𝗱𝗣𝗿𝗲𝘀𝘀 | 𝗦𝗵𝗼𝗽𝗶𝗳𝘆 | 𝗔𝗣𝗜 | 𝗲𝗖𝗼𝗺𝗺𝗲𝗿𝗰𝗲 | 𝗟𝗮𝗻𝗱𝗶𝗻𝗴 𝗽𝗮𝗴𝗲 ✅ 𝗗𝗲𝗹𝗶𝘃𝗲𝗿𝗲𝗱 𝟱𝟬𝟬+ 𝗙𝗮𝘀𝘁 & 𝗛𝗶𝗴𝗵 𝗰𝗼𝗻𝘃𝗲𝗿𝘀𝗶𝗼𝗻 𝘄𝗲𝗯𝘀𝗶𝘁𝗲𝘀 ⭐𝗥𝗮𝘁𝗲𝗱 𝟱/𝟱 | 💯 𝗙𝗿𝗲𝗲 𝗯𝘂𝗴 𝗳𝗶𝘅 | ❤️ 𝗣𝗼𝘀𝘁-𝗹𝗮𝘂𝗻𝗰𝗵 𝘀𝘂𝗽𝗽𝗼𝗿𝘁 I help companies build and scale e-commerce stores, corporate sites, and custom web solutions that increase sales and save time. What I can do for you: - Full Shopify store setup & customizations (themes, apps, API) - WordPress & WooCommerce development (speed, security, SEO) - Laravel & API integrations (Stripe, Wallee, custom automations) - Performance optimization (Core Web Vitals, fast loading) - Total custom solutions - Ongoing support and audits Why work with me? - AI-driven workflow saving 50% costs and doubling speed. - Free bug fix. - Post-launch support. - 10+ years of experience in web development. - 50+ successful projects for clients in the US, UK, and EU. - Always on time, transparent communication, long-term reliability. Let’s talk about your project — I’ll help you launch or improve your website so it brings measurable results.
BinarGear
Associated with
BinarGear
$600+
earned
Yurii Y.
$45/hr
100% Job Success
$80K+ earned
Available now
Offers consultations
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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.
Yurii Y. has worked .
Sergii M.
$55/hr
99% Job Success
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🏆 Top Rated Plus (Top 1% Upwork talent) ☕ Started working as web developer in 1999 🔥 Expertise in front-end, back-end, and server administration 🔐Always keeping in mind security and productivity aspects 🎓Master and bachelor degrees in computer science Let's make your project successful! 🚀🚀🚀
Sergii M. has worked .
Ihor M.
$35/hr
100% Job Success
$100K+ earned
Available now
Offers consultations
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Java developer with 5+ years of building full-stack applications, backend systems, REST APIs, microservices, cloud infrastructure on AWS, GCP, and Azure, database design in PostgreSQL and MySQL, and modern frontend frameworks like React and Angular. I've shipped 35+ production projects across fintech, logistics, telecommunications, retail, SaaS, healthcare, enterprise and more. On the backend, my core stack is Java, Spring Boot, and Spring Framework, with REST APIs, Hibernate/JPA, PostgreSQL, MySQL, MongoDB, and SQL for persistence. For infrastructure I work across AWS, GCP, and Azure, and I'm comfortable with Docker for containerisation and environment consistency, Kubernetes, and CI/CD pipelines. When a project needs it, I also write Python, Node.js, and front-end code in React or Angular, including JavaScript for client-side logic. I have working experience with PHP for web backend tasks, and I've applied Python beyond scripting, including data processing pipelines and ML-adjacent work such as model integration and feature engineering. The impact side: over 5 years I've designed 120+ REST APIs, built 10+ microservice architectures from the ground up, and worked on systems serving anywhere from 10K to 500K+ users depending on the project scale. Performance work is something I take seriously: on several engagements I've cut API response times by up to 60% and improved overall system performance by 40%+ through targeted refactoring and architectural improvements, rather than costly rewrites. I've also worked extensively with enterprise-level database schemas, writing and optimising complex SQL queries, indexing strategies, and data models across tables with 100K+ records. The production systems I've maintained have consistently held 99.9% uptime, which at that scale doesn't happen by accident. It comes from solid monitoring, thoughtful deployment practices, and knowing where the failure points are before they become incidents. My clients get clear communication, fast responses, and code that's actually maintainable six months later. I'm business-focused; I care whether the thing solves your problem, not just whether it compiles. As one client put it: "he doesn't just write code; he thinks about why we need it in the first place." Not only a Java developer, I've led teams, mentored junior devs, and run cross-functional projects where the technical and the human side both needed managing. Clean code matters. So does knowing when to push back, when to unblock someone, and when to just make the call. I am always open to long-term collaborations and challenging software engineering projects involving Java, Spring Boot, React, Angular, cloud systems, microservices architecture, and modern backend engineering. Need a Java developer who ships clean code and tells you when you're building the wrong thing? That's the conversation worth having. Drop me a message.
Ihor M. has worked .
Eastoner
Associated with
Eastoner
$500K+
earned
Oleh K.
$29/hr
100% Job Success
$70K+ earned
Available now
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Stop fighting with slow, bloated WordPress sites. I build high-performance, scalable websites that look exactly like your design and stay lightning-fast. As a Top Rated Plus developer with 2,400+ hours on Upwork, I specialize in clean architecture using Elementor and Advanced Custom Fields (ACF) to eliminate "plugin-hell." How I help your business grow: - Figma to WordPress: 100% design fidelity (Pixel-Perfect) with responsive layouts for all devices. - Custom ACF Logic: Complex dynamic content, custom post types, and intuitive back-ends so you can easily manage your site. - Speed & SEO Optimization: 90+ Google PageSpeed scores. Fast sites convert better. - WooCommerce Expert: Scalable e-commerce solutions that actually drive sales. - Clean Code: Utilizing PHP, CSS, and JavaScript to extend Elementor’s capabilities where others fail. - Core Stack: WordPress, Elementor Pro, ACF, WooCommerce, PHP, JS, CSS. Ready to build a powerful platform that reflects your brand? Let’s jump on a quick call to discuss your project!
Oleh K. has worked .
Kikson Digital
Associated with
Kikson Digital
$20K+
earned