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Experienced Java Developer with 5+ years in backend development. Proficient in Java, Spring, Quarkus, and cloud technologies. Strong expertise in microservices, databases, and DevOps tools. Adept at designing scalable architectures and optimizing application performance. Passionate about writing clean, maintainable code and mentoring junior developers.

𝟭𝟳𝟬 𝗽𝗿𝗼𝗷𝗲𝗰𝘁𝘀. 𝟮𝟮 𝘆𝗲𝗮𝗿𝘀. 𝗕𝘂𝗶𝗹𝘁 𝘁𝗼 𝘀𝗰𝗮𝗹𝗲. 𝗕𝘂𝗶𝗹𝘁 𝘁𝗼 𝗽𝗲𝗿𝗳𝗼𝗿𝗺. 𝗕𝘂𝗶𝗹𝘁 𝗳𝗼𝗿 𝗴𝗿𝗼𝘄𝘁𝗵. 🔥 𝐅𝐫𝐞𝐞 𝟐𝟎 𝐡𝐨𝐮𝐫𝐬 𝐨𝐟 𝐩𝐥𝐚𝐧𝐧𝐢𝐧𝐠 𝐟𝐨𝐫 𝐲𝐨𝐮𝐫 𝐧𝐞𝐰 𝐩𝐫𝐨𝐣𝐞𝐜𝐭 (DM "Free") 🔥 𝐅𝐫𝐞𝐞 𝐜𝐨𝐝𝐞 𝐫𝐞𝐯𝐢𝐞𝐰 𝐟𝐨𝐫 𝐲𝐨𝐮𝐫 𝐞𝐱𝐢𝐬𝐭𝐢𝐧𝐠 𝐩𝐫𝐨𝐣𝐞𝐜𝐭 (DM "Free") Main focus: ✅𝐅𝐮𝐥𝐥-𝐒𝐭𝐚𝐜𝐤 𝐖𝐞𝐛 & 𝐒𝐚𝐚𝐒 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭: build production-ready web applications, SaaS platforms, customer/admin portals, dashboards and complex business systems from A to Z with Java, Spring Boot, Spring Cloud, Angular, React, REST APIs, PostgreSQL/MySQL, AWS, Docker and Kubernetes. ✅𝐂𝐨𝐦𝐩𝐥𝐞𝐱 𝐒𝐲𝐬𝐭𝐞𝐦𝐬 & 𝐀𝐏𝐈 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧𝐬: design scalable backend architecture, business logic, APIs, WebSockets, data hubs, gateways and third-party integrations using Java, Spring Boot, REST, SOAP, OAuth and event-driven technologies. ✅𝐀𝐈 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭 & 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧: embed AI-powered features into SaaS and business software using Claude, Codex, MCP, RAG, Vertex AI and Spring AI for analytics, automation, predictive systems and AI over business data. ✅𝐂𝐥𝐨𝐮𝐝 & 𝐒𝐜𝐚𝐥𝐚𝐛𝐥𝐞 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬: architecture and development of cloud-native, serverless and scalable applications using AWS, GCP, Docker, Kubernetes, ECS, EKS, Lambda, RDS, SQS/SNS and zero-downtime deployment. ✅𝐑𝐞𝐥𝐢𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠: structured review of your application, architecture, AWS infrastructure, deployment process, monitoring, APIs and operational dependencies, followed by a prioritized remediation roadmap. ✅𝐏𝐎𝐒 𝐚𝐧𝐝 𝐌𝐮𝐥𝐭𝐢-𝐒𝐭𝐨𝐫𝐞 𝐂𝐨𝐦𝐦𝐞𝐫𝐜𝐞: POS, KDS, checkout, payments, catalog, ordering, inventory, loyalty, reporting and multi-store commerce software for businesses operating across physical locations and online storefronts. ✅𝐈𝐨𝐓 𝐅𝐥𝐞𝐞𝐭 𝐌𝐚𝐧𝐚𝐠𝐞𝐦𝐞𝐧𝐭: build secure IoT, telemetry, remote diagnostics and predictive maintenance platforms for manufacturers, service teams and operators managing connected devices at scale using AWS IoT, MQTT, data streaming and cloud analytics. ✅𝐉𝐚𝐯𝐚 𝐄𝐜𝐨𝐬𝐲𝐬𝐭𝐞𝐦 𝐌𝐨𝐝𝐞𝐫𝐧𝐢𝐳𝐚𝐭𝐢𝐨𝐧: modernize Java-based enterprise systems in controlled stages using Java, Spring, Spring Boot, EJB, Oracle, WebLogic, WebSphere and JBoss/WildFly while preserving critical business functionality. ✅𝐄𝐧𝐭𝐞𝐫𝐩𝐫𝐢𝐬𝐞 𝐒𝐨𝐟𝐭𝐰𝐚𝐫𝐞 𝐑𝐞𝐬𝐜𝐮𝐞: take over, understand, stabilize and safely continue development of complex Java, Spring and AWS systems when the existing team, architecture or delivery process is no longer reliable. ================================================ WE EARN/SAVE MONEY💰 FOR OUR CUSTOMERS by: • allowing their business to expand (or start sometimes:) • automating processes and reducing operational cost • using newer and more efficient technology • long-run cost reduction because of high-quality software. ================= Some tech below =============== ✓ Full-Stack Web: Java, Spring Boot, Spring Cloud, Angular, React, JavaScript, Bootstrap, OAuth. ✓ Java/Spring: Spring Boot, Spring MVC, Spring Web, Spring Security, Spring Data, Spring AI. ✓ Java/JavaEE: EJB, JSP/JSF/RichFaces, Oracle ADF, JavaFX. ✓ APIs & Integrations: REST, SOAP, XML-RPC, WebServices, WebSockets, Swagger/OpenAPI. ✓ Cloud: AWS, Google Cloud, Docker, Kubernetes, ECS, EKS, cloud-native apps, scalable clusters, zero-downtime deployment. ✓ AI: Codex, Claude, MCP, RAG, Vertex AI, Spring AI. ✓ Databases: Oracle, PostgreSQL, MySQL, PL/SQL, AWS RDS, Aurora, Cassandra, Redis, MongoDB, Neo4j, HDFS, S3/Parquet, JPA, custom ORMs. ✓ AWS: EC2, Kinesis, Athena, Redshift, DynamoDB, Lambda, IoT, SQS/SNS, CloudFront, Route53, API Gateway. ✓ Data streaming: AWS Kinesis, Firehose, SQS/SNS, Kafka, Camel, RabbitMQ. ✓ Servers: Tomcat, WebLogic, JBoss/WildFly, WebSphere. ✓ Performance optimization: JMeter, JProfiler, AWS X-Ray, GTMetrix, Gatling. ✓ Version control: Git, GitHub, Bitbucket, GitLab, SVN. ✓ CI/CD: Bamboo, Jenkins, Circle CI, Sonar, Bitbucket Pipelines, GitHub Actions, AWS CodeBuild/CodeDeploy. ✓ Other: Maven, Nexus, Gradle, Ant, Workflow Automation, Performance Optimization, QA Automation. 𝐑𝐞𝐚𝐝𝐲 𝐭𝐨 𝐛𝐮𝐢𝐥𝐝? 𝐌𝐞𝐬𝐬𝐚𝐠𝐞 𝐦𝐞 - 𝐥𝐞𝐭’𝐬 𝐠𝐞𝐭 𝐢𝐭 𝐦𝐨𝐯𝐢𝐧𝐠.

Mobile Flutter Developer with DevOps expertise — building cross-platform iOS & Android apps and owning the full delivery pipeline: AWS, Kubernetes, Ansible, Terraform, CI/CD. 10+ years in software engineering. I deliver production-ready Flutter apps together with the infrastructure that builds, deploys, and runs them. Flutter Development: Flutter & Dart — performance optimization, clean architecture, responsive UI/UX State management — BLoC, Provider, MobX, Riverpod Animations & graphics — custom animations, CustomPainter, Rive/Lottie, shaders Maps & geolocation — Google Maps, Mapbox, real-time tracking Native integrations — platform channels, C++ libraries, real-time audio processing App Store & Google Play deployment, release management DevOps & Cloud Infrastructure: Infrastructure as Code — Terraform, Ansible; Kubernetes orchestration with Helm CI/CD — automated builds, testing, and deployments (GitHub Actions, Jenkins, GitLab CI, Fastlane, Docker), including mobile release pipelines to App Store and Google Play Monitoring & observability — Prometheus, Grafana Cloud platforms — AWS, Google Cloud (GCP), Hetzner; Linux server administration Firebase & Supabase — auth, real-time database, cloud functions, hosting Backend Development: Node.js, Python, Java, Dart backends API design — REST, GraphQL, gRPC, WebSockets Databases — PostgreSQL, MySQL, MongoDB, Redis, SQLite AI & LLM: AI/LLM integrations in production apps — OpenAI, Anthropic (Claude), Gemini APIs AI-assisted development workflow — Claude Code and OpenAI Codex Experience: multiple production apps delivered end-to-end as a solo developer — UI, backend, cloud infrastructure, and deployment automation. Comfortable owning a product fully or working inside an experienced team. I care about code quality, long-term maintainability, and delivering real value — not just completing tasks. If you need someone who understands mobile development, backend, and the infrastructure that connects them into a working product — I'd be glad to help. = = = Career Highlights = = = Oct 2024 – Present — Flutter Developer & DevOps Engineer Building production Flutter apps end-to-end with cloud infrastructure and deployment automation: AI/LLM-powered features, real-time systems, infrastructure as code. Working independently, owning products from UI to deployment. Stack: Flutter/Dart, Python, AWS & Google Cloud, Kubernetes, Terraform, Ansible, Docker, Firebase, Supabase, PostgreSQL, MySQL, Redis, MongoDB Dec 2018 – Oct 2024 — Flutter Developer Six+ years of Flutter in production since its early releases: multiple apps shipped to App Store and Google Play, real-time and data-driven architectures, solo ownership from UI to backend. Stack: Flutter/Dart, Supabase, Google Cloud, Firebase, PostgreSQL, SQLite, Linux 2015 – 2018 — Full-Stack JavaScript Developer Web applications and data visualization for production use. Stack: JavaScript (React, D3), Node.js, Python/Django, MongoDB 2010 – 2013 — Java Developer Enterprise web applications. Earned Oracle Certified Professional, Java Programmer. Stack: Java, GWT, Oracle DB 2006 – 2008 — Web Developer First commercial projects; Linux as a daily driver since then. Stack: PHP, JavaScript, MySQL, Linux = = = Technologies = = = Flutter • Dart • BLoC • Provider • Riverpod • MobX • CustomPainter • Rive • Lottie • Google Maps • Mapbox • Push Notifications • Firebase Cloud Messaging • In-App Purchases • Hive • CI/CD pipeline • GitHub Actions • Jenkins • GitLab CI • Fastlane • Docker • Kubernetes • Helm • Terraform • CloudFormation • Ansible • Prometheus • Grafana • Bash scripting • AWS • EC2 • S3 • EKS • Lambda • Google Cloud • GCP • Firebase • Supabase • Linux • Node.js • Python • Django • PostgreSQL • MySQL • MongoDB • Redis • REST API • GraphQL • gRPC • WebSockets • LLM integration • RAG • AI chatbot • OpenAI API • Anthropic API • Claude API • Gemini API • Claude Code • OpenAI Codex • Stripe • App Store • Google Play

Minecraft Server Developer Extraordinaire Hello, I'm Pawel, a seasoned Minecraft server developer with over 7 years of experience in crafting and optimizing immersive gaming environments. Expertise: 🛠️ Minecraft Server Development: Crafting robust servers and plugins, staying updated with the latest trends. 💻 Java Programming: Creating efficient, secure, and high-performance code. 🧰 Development Tools: Skilled in IntelliJ IDEA and managing databases with T-SQL and PL/SQL. ⚙️ Systems Management: Expert in managing and optimizing Minecraft server systems. 🌐 Server Technologies: Proficient in Paper (Spigot) and BungeeCord configuration. 🚀 Redis: Extensive knowledge in using Redis for caching, pub/sub messaging, and synchronizing multiple servers for real-time data consistency. 🔌 API Integration: Enhancing functionality and connectivity with API integrations. 🖥️ Swing Applications: Developing modern and functional Swing applications. 🤖 Additional Skills: Web scraping, automation, algorithm optimization, and bot development. Collaboration: Passionate about creating seamless Minecraft experiences. Let's collaborate to bring your Minecraft vision to life. Contact: Ready to transform your Minecraft project? Contact me today and let's craft extraordinary adventures together.

🏆 𝗧𝗢𝗣 𝗥𝗔𝗧𝗘𝗗 𝗣𝗟𝗨𝗦 🏆 ✅ Mobile App Developer 7+ years of experience ✅ SaaS Mobile App Developer 5+ years ✅ 35 mobile app development jobs completed successfully ✅ Android and iOS Mobile Expert ✅ Built 27+ UX-first Mobile App development jobs for 22 companies ✅ On-Time and Cost-Effective Delivery ✅ Future-Proof Solutions Showing a Minimum 41% ROI ✅ 4354 mobile app development hours on Upwork and still counting ✅ 100% Job Success in mobile app development (Client Satisfaction Ratio) ✅ 98% of Clients Recommended working with me ✅ 80% Long-term Repeat Clients ✅ 7+ years of experience in mobile app development, 6 years experience in iOS mobile app development, 7 years experience in Swift and Kotlin, 4 years experience in Flutter, React Native, 2 years experience in KMM, KMP Full stack mobile app developer and mobile app UI UX designer with 7+ years of experience in Mobile App Development, specializing in iOS, Swift, Android, Kotlin, KMM, Kotlin Mutliplatform / KMP, React Native, and Flutter. I have successfully delivered 120+ mobile applications in different roles as mobile app developer, flutter app developer, flutter full stack developer, flutter flow, mobile app design, mobile ui ux designer, swift ios developer, android developer, kotlin developer, react native developer, mobile game developer achieving a 5-star rating on Upwork and helping clients scale their businesses with high-performance solutions. Apart from mobile app development, I specialize in Mobile App Design for both iOS and Android, as well as Web App Design for SaaS platforms. My expertise extends to Interaction Design, User Flow Design, and creating seamless User Experience (UX Design) and User Interface (UI Design). I follow a Design Thinking approach, ensuring every solution is user-centered and problem-solving. My process includes UI/UX Wireframing, Prototyping, and building Style Guides or UI-kits for consistent branding. I perform Design Audits and Design QA to maintain high standards across all projects. 🛠️ Design Tools: My designs come to life through powerful tools like Figma, Zeplin, and InVision for prototyping and collaboration. I leverage Adobe Illustrator, Adobe Photoshop, and Adobe XD for detailed visual design. For complex wireframes and flow mapping, I turn to Axure, Sketch, and Balsamiq. I also use Miro and Abstract for brainstorming and version control, while project communication and management happen in Slack and Jira. Our Expertise at a Glance • Mobile App Development: Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, Flutter, and more. • Website and Full Stack Development: Crafting seamless back-end experiences with .Net, Python, Java, Javascript, React.js, Angular.js, Node.js, MERN, MongoDB, PHP, etc. • Logo & UI/UX Design: Bringing your ideas to life with Adobe XD, Photoshop, Sketch, Figma, etc. • End-to-End Solutions: From logo design, UI/UX development, workflow setup, testing to deployment in app stores, we've got it all covered. We do not use v0.dev lovable.app CursorAI, Cursor, Windsurf, Trae, GitHub Copilot, Tabnine, Qodo, Devin AI, and AutoDev for speed up coding, we know other methods to do it efficiently. We offer a comprehensive range of development services across mobile, web, and cloud platforms. Our mobile app development expertise includes building Android and iOS applications using technologies such as Flutter, Swift, Objective-C, React Native, and Xamarin, optimized for both smartphones and tablets with a focus on cross-platform compatibility. In website and full stack development, we work with .NET technologies, including full stack .NET development, .NET Core, and Python with Django. Our team is experienced in developing both backend systems and user-friendly, responsive web interfaces, as well as working with various CMS platforms. Our DevOps and DevSecOps capabilities cover cloud infrastructure and automation, leveraging tools like AWS, Azure, Docker, Kubernetes, GitLab CI, Ansible, and Terraform to build secure and scalable deployment environments. We also build cross-platform and web applications using frameworks like Three.js and design tools such as Webflow, creating visually engaging and functional user experiences across devices. Additionally, we are well-versed in integration and automation tools, including WebSockets, data integration, the ABP Framework, Discord API, and Autotask, allowing us to create seamless connectivity and workflow automation between systems. Talent Good Knowledge, Talented, Experienced, Skilled, Strong Experience, Proven Experience, Agency, Team, Company, Specialist, Proven Track Record, Strong Background, Write Clean Code, Deep Expertise, Bring to Life, Cross-platform, Attention to Detail, Long Term. ⚡️ AVAILABLE FOR NEW PROJECTS ⚠️ Press Invite Button on my page and let's talk.

Over the last 5 years, i worked on TeamLead/CTO position, and have developed a wide range of systems and services using C++/C#/Golang/Java/Javascript/PHP/SQL/NoSQL including multiple android application, geosocial network, browser-like unix system daemon, CORBA bridgess for Forex broker and countless websites.I have extensive experience in drafting technical specifications, in collaboration with non-IT professionals. My core competency lies in knowledge of wide range of technologies in many areas (android, networking, high-load, user interface design), I can quickly look into your needs and provide optimum solutions to your tasks, identify possible problems and suggest ways to solve them.