Hire the Best Kotlin Developers

Need someone who can build, stabilize and scale your Android product? You just found him 🤝 📊 12+ years in mobile delivery 📊 20+ Android-focused projects 📊 10+ years supporting regulated and business-critical products 📊 Experience with compliance-ready apps, secure payments, backend-heavy systems and Software Development I help companies create secure, maintainable, high-performance apps for Healthcare, FinTech and consumer products. Core Expertise 🔹 Native Android engineering with modern architecture and Software Design 🔹 Kotlin-first development with maintainability in mind 🔹 Legacy modernization from Java to Kotlin 🔹 Secure integrations, performance tuning, release stability 🔹 Product delivery for Healthcare, FinTech, consumer platforms and Mobile App Development I’m an android developer focused on products where reliability and clean architecture matter. As a kotlin developer, I build scalable solutions with android kotlin best practices, Jetpack tooling and AOSP awareness. Clients come to me for android developer kotlin expertise when they need stability, lower technical debt and growth. I work as an android app developer on products that need more than interface implementation. I support teams with android app development for secure solutions where every android app stays maintainable after launch. My background: improving an android application used by thousands of users, integrating backend systems, payment flows, and healthcare-grade data handling. That is why companies hire me as an android mobile developer ( android mobile app developer ) when they need delivery. What I Do Best ✅ Android development using Kotlin and Java ✅ Architecture design with MVVM, Clean Architecture, modularization ✅ Backend communication, authentication and payment integrations ✅ Performance optimization, debugging, maintenance and release support ✅ Application Improvement for live mobile products ✅ Solo delivery or collaboration inside a larger team My strongest specialization is android developer kotlin work. I often join teams that need android developer kotlin java skills to modernize legacy code, migrate modules, and improve release quality without a full rewrite. That work benefits from practical experience as a java developer and from thinking like an android kotlin developer who can handle new features and stabilization. Relevant Experience Highlights 🔸 Healthcare mobile applications with compliance-aware architecture 🔸 Performance optimization and crash-rate reduction 🔸 Secure data handling and app stability improvements 🔸 Secure apps with payment integration and transaction-safe flows 🔸 Backend integrations with PHP, Python, JavaScript, and REST APIs 🔸 Collaboration with iOS, backend, QA, and web teams 🔸 Ability to scale from one engineer to a delivery team I also have experience with android ble and android bluetooth features for pairing flows and reliable data exchange. Whether I contribute to an android mobile app or support an existing codebase as a mobile developer, I focus on release readiness. Tech Stack 🔸 Android kotlin with Jetpack, Compose, Android SDK, AOSP 🔸 Java, Firebase, secure cloud services, CI/CD 🔸 REST APIs, secure auth, payment gateways 🔸 Node.js, JavaScript, C#, SQL for backend alignment 🔸 Git, Android Studio, release workflows, crash analysis 🔸 MVVM, Clean Architecture, modular apps, scalability-first mindset My work is rooted in native Android, but I also understand broader product ecosystems. I collaborate effectively as an ios developer ( ios app developer ) when cross-platform alignment matters, including iOS Development discussions with teams using Swift. I have worked alongside teams using react native and reviewed delivery implications where flutter developer was involved, though I do not present those as my core specialization. That exposure helps me operate as an android developer and product-minded mobile app developer within cross-functional teams. Team & Product Collaboration 🔹 Coordination with a rest api developer 🔹 Alignment with web application development 🔹 Communication with a web developer or front end developer 🔹 Familiarity with database builder, django, and python automation Support I Can Provide ✔️ Build a mobile app from scratch ✔️ Join an existing product as an app developer android ✔️ Refactor legacy code and modernize architecture ✔️ fix android application bugs and improve release readiness I do not position myself as a wordpress, magento, game developer or unreal engine specialist and I do not use unrelated positioning such as android developer india. Even when someone types android develoer, they usually need a senior specialist who can take ownership. I built mobile applications for autism-related projects with intuitive user experience. 📬 If you need an android developer who can improve an existing product, build a reliable solution from scratch or support growth with kotlin developer depth, send me a message.

🟢 AVAILABLE TODAY, JUNE 16 ⚡ Message me "AUDIT" - get a free 30-min technical review of your app idea, architecture, or existing codebase. No sales pitch. Just honest engineering feedback. I'm Siarhei - ex-CTO × 3 funded startups, CEO of Sparkler Soft. We build native iOS & Android products that ship, scale, and raise. 🔵 PROVEN RESULTS ◈ iHairium - AI Hair Diagnostics (live on App Store) Neural network · 100K+ training images · 95-98% accuracy $600K angel round + $5M seed valuation Revenue ×10 to ×1000 per month in early stages Google & Amazon grants · 1,000+ clinic partners onboarded ◈ Eco-Go - Electric Scooter Sharing Platform iOS + Android + Backend + IoT + Admin Panel AWS IoT Device Management · Swappable battery infrastructure Named "Best Startup of the Region" ◈ Optics Platform [White-label · Strict NDA] AI-assisted frame & lens selection via device camera Active in 60+ countries · 1,000+ fitting points worldwide 10+ years on market · Award-winning at international exhibitions ◈ Chibbis - Unified Food Delivery Service 600+ restaurants · 150+ cities across Russia iOS + Android + Web + Admin Panel + CMS One of the country's leading delivery platforms ◈ CoinForShop - Crypto Marketplace iOS + Android + Web (React) Non-custodial wallets · Smart contract payments BTC · ETH · BCH · LTC · XMR · TRX · 100% MVP delivered ◈ Azarium - NFT Real Estate Investment Platform Fractional property ownership via blockchain MAS-regulated · Live construction webcam in-app Min investment from $200 · Expected ROI 30–60% 🟠 WHAT WE BUILD → HealthTech & AI On-device ML · Camera diagnostics · Neural networks TensorFlow Lite · Core ML · OpenCV → FinTech & Crypto Wallets · KYC/AML · Stripe · Smart contracts · NFT → Mobility & IoT GPS · BLE · AWS IoT · Scooter & bike sharing Telematics · Real-time fleet management → Marketplace & Delivery Full-stack: app + backend + admin panel + CMS → API Integrations Stripe · Mapbox · Sumsub · Firebase · any third-party 🟡 TECH STACK Mobile: Swift · SwiftUI · Objective-C · Kotlin · Java Backend: Java Spring Boot · Node.js · NestJS · Golang Frontend: React · Next.js AI/ML: TensorFlow Lite · Core ML · OpenCV Cloud: AWS · GCP · Azure · Docker · Kubernetes · CI/CD Data: PostgreSQL · MongoDB · Redis · Elasticsearch Security: OAuth2 · OIDC · JWT · Keycloak · Biometrics · IAP 👉 Message "AUDIT" right now - 30 minutes to understand if we're the right fit. No obligation. No pitch. Just clarity.

I’m an Android developer specializing in Kotlin and Jetpack Compose. I usually work with clients who want a developer they can rely on long-term someone who can take ownership, keep the app stable, and ship improvements consistently. I can help with: • Payment & POS SDK integrations (native Android, terminals, receipts, transaction states) • Fixing issues in existing apps (bugs, crashes, performance) • Modern UI with Compose / Material 3 • API + Firebase + Room/SQL integrations • Play Console releases (signing, build setup, store-ready delivery) Working style: • I communicate clearly and send frequent updates • I prefer clean MVVM-based code and maintainable structure (easy to extend later) If we work well together, I’m open to an ongoing monthly setup (fixed hours or retainer) so you don’t have to keep switching developers. If you share what you’re trying to achieve (bug fix, new feature, payment integration, UI refresh), I’ll suggest the fastest, cleanest way to move forward.

Full Stack Developer (7 Years) | Full-Time Freelancer I provide one-stop software solutions for startups and businesses. Instead of hiring separate frontend and backend developers, I build your entire product from the ground up—from server architecture to cross-platform clients. What I Deliver: - End-to-End Lifecycle: Architectural design - Backend/API - Pixel-perfect UI - Market Release. - Cross-Platform Expansion: Seamless apps for Android, iOS, Web, Desktop, and Wear OS with high performance. - Scalable Backend Systems: Fast, reliable, and maintainable backend services powered by Rust or Kotlin for long-term product growth. - IoT & Hardware Expertise: Advanced integration for Android-based IoT clients, including Kiosk Mode, Serial Port communication, etc. - Fast Delivery: Skilled in leveraging AI agents to speed up development, reduce repetitive work, and quickly turn ideas into production-ready features. Core Tech Stack: - Frontend & Mobile: Kotlin Multiplatform, Compose Multiplatform - Backend: Axum (Rust), Ktor (Kotlin) I turn sketches into flawless, scalable apps. As a full-time freelancer, I guarantee fast, transparent communication and dedicated availability. Let’s build something great together.

🚀 𝐓𝐡𝐞 𝐀𝐩𝐩 𝐒𝐭𝐨𝐫𝐞 𝐢𝐬 𝐜𝐫𝐨𝐰𝐝𝐞𝐝, 𝐚𝐧𝐝 𝐚𝐯𝐞𝐫𝐚𝐠𝐞 𝐝𝐞𝐬𝐢𝐠𝐧 𝐣𝐮𝐬𝐭 𝐝𝐨𝐞𝐬𝐧’𝐭 𝐜𝐮𝐭 𝐢𝐭 𝐚𝐧𝐲𝐦𝐨𝐫𝐞. Whether it’s a mobile app, a macOS desktop tool, or a UI that converts users demand performance, beauty, and seamless experience. That’s where I come in. I'm a 𝐌𝐨𝐛𝐢𝐥𝐞 & 𝐦𝐚𝐜𝐎𝐒 𝐀𝐩𝐩 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 + 𝐔𝐈/𝐔𝐗 𝐃𝐞𝐬𝐢𝐠𝐧𝐞𝐫 with a proven record of building high-performance apps and clean, conversion-driven designs. I specialize in delivering Swift-powered solutions that combine sleek front-ends with rock-solid back-end logic. 🔧 𝐖𝐡𝐚𝐭 𝐈 𝐎𝐟𝐟𝐞𝐫: ✔ iOS Development (Swift, SwiftUI, Combine, CoreData) ✔ macOS Desktop App Development using native frameworks & APIs ✔ MVVM Architecture for scalable, clean codebases ✔ Firebase Integration (Realtime DB, Auth, Cloud Messaging, Firestore) ✔ Custom PDF Workflows with PDFKit ✔ Smooth Lottie Animations for next-level UI ✔ API Integration + JSON Serialization with precision ✔ UI/UX Design in Figma – From wireframe to final screen ✔ Responsive Design for all screen sizes (Mobile + Desktop) ✔ Landing Pages & Web UI that convert visitors into users 💡 𝐖𝐡𝐲 𝐂𝐥𝐢𝐞𝐧𝐭𝐬 𝐇𝐢𝐫𝐞 𝐌𝐞: ✔ 6+ years of experience across mobile, desktop & UI design ✔ Cross-disciplinary skills I don’t just code, I design with purpose ✔ Clean, modular code that’s easy to scale and maintain ✔ Great communication, deadline-oriented, and focused on ROI ✔ Solutions built around real user behavior not just trends 🏆 𝐑𝐞𝐜𝐞𝐧𝐭 𝐏𝐫𝐨𝐣𝐞𝐜𝐭𝐬: 🔗 𝐏𝐨𝐫𝐭𝐟𝐨𝐥𝐢𝐨 𝟏 – 𝐒𝐰𝐢𝐟𝐭𝐔𝐈 + 𝐏𝐃𝐅𝐊𝐢𝐭 𝐀𝐩𝐩 𝐰𝐢𝐭𝐡 𝐅𝐢𝐫𝐞𝐛𝐚𝐬𝐞 𝐒𝐲𝐧𝐜 Developed a cross-platform app (iOS + macOS) using SwiftUI and PDFKit, integrated with Firebase for real-time data sync and custom PDF export workflows. 🔗 𝐏𝐨𝐫𝐭𝐟𝐨𝐥𝐢𝐨 𝟐 – 𝐦𝐚𝐜𝐎𝐒 𝐃𝐞𝐬𝐤𝐭𝐨𝐩 𝐀𝐩𝐩 𝐰𝐢𝐭𝐡 𝐂𝐨𝐫𝐞𝐃𝐚𝐭𝐚 + 𝐂𝐨𝐦𝐛𝐢𝐧𝐞 Delivered a clean, MVVM-structured desktop app using CoreData and Combine for smooth UI updates and persistent storage. 🔗 𝐏𝐨𝐫𝐭𝐟𝐨𝐥𝐢𝐨 𝟑 – 𝐀𝐏𝐈-𝐏𝐨𝐰𝐞𝐫𝐞𝐝 𝐀𝐩𝐩 𝐰𝐢𝐭𝐡 𝐋𝐨𝐭𝐭𝐢𝐞 𝐀𝐧𝐢𝐦𝐚𝐭𝐢𝐨𝐧𝐬 Built a visually rich app featuring Lottie animations and seamless third-party API integration for enhanced interactivity. 🔗 𝐏𝐨𝐫𝐭𝐟𝐨𝐥𝐢𝐨 𝟒 – 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐢𝐯𝐞 𝐒𝐡𝐨𝐩𝐩𝐢𝐧𝐠 𝐀𝐩𝐩 𝐔𝐈 𝐢𝐧 𝐅𝐢𝐠𝐦𝐚 Designed a mobile shopping app UI in Figma with responsive layouts, optimized for usability across iPhone and iPad screens. You can explore these live projects in my portfolio for real examples of my code, design, and delivery standards. 👥 𝐖𝐡𝐨 𝐈 𝐖𝐨𝐫𝐤 𝐖𝐢𝐭𝐡: Startups & Entrepreneurs launching new mobile or macOS apps Agencies who need reliable developers/designers for client work Businesses looking to redesign or optimize mobile/Desktop UI/UX Tech teams who need clean architecture, API handling, and modern Swift coding 🎯 𝐓𝐞𝐜𝐡 𝐒𝐭𝐚𝐜𝐤 & 𝐓𝐨𝐨𝐥𝐬: Languages/Frameworks: Swift, SwiftUI, Combine, Firebase, MVVM, CoreData Design: Figma, Lottie, Responsive Design Tools: PDFKit, REST APIs, JSON serialization, Git You’ve got a product that deserves to perform and look outstanding let’s make sure your users love every tap, swipe, and click. Click “Invite” and let’s build something that scales, converts, and stands out.

I'm an Android Developer / Mobile Developer with 10 years of experience helping small businesses and startups translate their vision into scalable, high-performance apps from 0 to launch using the latest technologies ( Kotlin , Coroutines , Jetpack Compose , Kotlin Multiplatform, and AI agents ). I specialize in: - on-device AI integration using MediaPipe / TFLite / Google ML Kit (Object detecton , Face and pose detection , Text summarizing / OCR , text-to-speech , speech-to-text , etc.); - building media, social, and everyday tools (not games); - fixing app performance , memory leaks , crashes and ANRs , especially in complex or “vibe-coded” apps. 🌟🌟🌟🌟🌟 Recent feedback : "I was particularly impressed by his strong attention to detail — nothing was overlooked, and the quality of the work consistently met high standards. He showed real commitment to the project, staying engaged and proactive throughout the development process. His regularity and consistency in delivering work made collaboration smooth and reliable." - Neil 🚀 Also I've been building my own Android apps so that gives me a deep understanding of not only a technical part but also ASO and monetization strategy. ✅️ Recent large-scale projects: --- PDF Maker & Reader (130k+ installs , 🌟4.6 on Google Play) Role: Android Developer / Android App Developer / Kotlin Developer I recently built this high-performance Android app from scratch based on Figma mockup using Kotlin. It allows users to quickly convert images to PDF and edit existing PDFs using a fast, local-first architecture. The app has achieved 130k+ downloads and 8k monthly active users on Google Play, with the crash rate lower than 0.1%. --- --- US Medical Education App (COMQUEST for COMLEX & COMAT Prep) Role: Android Developer / Android App Developer / Mobile Developer As part of an international team alongside iOS Developer and Web Developer, I built this Android app from scratch based on Figma designs for US medical students. Continue providing ongoing support for this project, ensuring the mobile app remains a stable and reliable tool for users. --- --- US Automotive Video Suite app Role: Android Developer / Android App Developer / Mobile Developer In collaborating with an iOS Developer and a Full Stack Developer, I built two native Android apps from scratch as a clone of iOS apps (Dealer Video Inventory and Dealer Video Suite) that allows dealers to capture high-quality vehicle inventory videos and photos. These projects helps dealers increase sales through personalized video. --- 🌟 🌟🌟🌟🌟 "Dmitri is a pleasure to work with. He's Android programming skills are exceptional. He's always professional and easy to work with. He is very methodical in his approach. Which at times has resulted in delivery scheduling slipping a little but I rather have a good product than a hastily put together product. We're continuing to work with Dima for other projects." - Philip Whether you are looking for a Mobile Developer to lead a new project or an Android Developer to optimize an existing Java / Kotlin codebase or optimize performance, my goal is to provide technical clarity and long-term stability. As a team player for cross-platform projects I have a proven track record of working alongside iOS developers to ensure smooth releases. I also have specific experience collaborating with Flutter Developers and Full Stack Developers to bridge the gap between cross-platform Flutter / React Native code and the system features specifically by developing custom Java / Kotlin modules to handle native Android OS functionality that standard Flutter plugins can't reach. --- 🚀 My core stack: 🔸️Languages: Java , Kotlin 🔸️UI: XML , Jetpack Compose 🔸️Architecture: MVVM , MVI , Clean Architecture 🔸️Native: Android SDK , Android Studio 🔸️Multiplatform: Kotlin Multiplatform ( KMM / KMP ) / Compose Multiplatform ( CMP ) 🔸️Key features: Camera , Photo & Video capture and edit using FFMpeg , OpenGL , OpenCV ; GPS , Location , Chat , Background syncronization , WorkManager and foreground services, ofline-first approach, on-device AI / LLM , VPN / WireGuard , ExoPlayer / Media3 🔸️On-device AI integration : Video analysis , Image recognition , Object detection , Face detection , Pose Detection , Camera stream analysis , Text-to-Speech , Speech-to-Text ( MediaPipe / Google AI Edge , TensorFlow / TFLite , Google ML kit ). 🔸️Cloud AI integration : OpenAI , Gemini API