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Backend Engineer (Java/Spring/AWS) helping startups move faster and fix backend issues. I help startups build and improve backend systems - from shipping new features fast to fixing performance and stability issues. I work mainly with Java (Spring Boot), PostgreSQL, Redis, and AWS, and I’m comfortable taking ownership of backend parts from API design to production deployment. Currently available for part-time work (10-20h/week), can start immediately. Recent results: • Reduced report latency from seconds to sub-second using Redis caching (TTL + watermark) • Led migration from Okta to Auth0 across multiple microservices • Built a B2B marketplace backend (Postgres + Elasticsearch) handling thousands of products with stable search I can help you with: • Building new backend features quickly • Stabilizing and improving an existing system • Fixing performance issues (DB queries, APIs, latency) • Designing clean and scalable backend architecture • Integrating external services and APIs I focus on writing clean, maintainable code and delivering solutions that work reliably under real-world load. If you need someone who can jump in and deliver quickly - feel free to reach out.

Backend systems become interesting when real traffic, real data, and real constraints arrive. I design, build, and fix Java/Kotlin systems at that point—from architecture and performance to production reliability. Most of my career has been spent building production backends in Java and Kotlin, usually with Spring Boot, AWS, Kubernetes, PostgreSQL, Redis, Elasticsearch, and ClickHouse. I also use Python, Go, and TypeScript when they’re a better fit. Typical work: • Designing and delivering new backend services • Untangling systems that are difficult to scale, change, or operate • Solving performance, reliability, data, search, and integration problems Clients value that I go deep enough to understand the whole system, communicate clearly, and stay accountable for the outcome. I stay hands-on from architecture to production. I ask difficult questions early, explain trade-offs without theatre, and prefer the simplest design that will hold up. Architecture is useful only if it survives implementation. Have a difficult backend problem? Send me the system, the constraint, and the outcome you need. I’ll tell you honestly whether I’m a good fit and what the first step should be.

Professional Summary • 12+ years developing JEE solutions for banks. Working mainly with those technologies: Java, Spring-boot , Spring MVC, Spring Security.... These applications work under MySQL, SQLServer, and Oracle databases; • 5+ years of designing and developing Restful microservices. • 3+ years of hands-on experience integrating SOAP Web Services, XML, and XSD systems. • 8+ years using Scrum in the software development process, where 3 of those years as Scrum Master; • 7+ Working experience designing, developing, and managing Java applications at AWS and/or Kubernets/Openshift cloud. • The main application container so far was Apache Tomcat, but I also had experience with JBoss and Websphere environments. Main skills: • Proactive, always aim to contribute to team objectives; • Focused on results without losing the quality sense; • Take problems ownership; • Flexible Other tools • Bug Tracking: JIRA, Redmine • Tests and Performance Analysis: Apache Jmeter, SoapUI • Version control: GIT,SVN • Others: IntelliJ, Maven, Eclipse

I'm a Liferay 7.4 developer with experience creating, migrating, and maintaining web portals for small and medium-sized businesses. I specialize in: Custom OSGi modules and Liferay Objects (data modeling + custom logic) Client Extensions and React for modern, decoupled UIs APIs with REST Builder and OpenAPI Integrations with external systems via REST/GraphQL Multilingual content Adapting Figma designs into responsive Liferay components and pages I focus on delivering clean, maintainable code, iterative project delivery, and clear communication. Collaboration through written updates is my standard to ensure smooth progress. I enjoy taking projects from initial design to production, solving technical challenges, and implementing solutions that scale. Additional Skills (Voice Work & Illustration) Alongside my development work, I collaborate on Spanish voiceover and TTS recording projects. I recently completed a 3-hour Spanish dataset for an Upwork Enterprise client, delivering clean, normalized mono audio (48 kHz / 24-bit) for AI training purposes. I also create hand-drawn pencil illustrations, including characters, portraits, and clean line-art drawings. My work is fully hand-drawn (no AI, no filters) and suitable for children's books, concept art, and technical sketches.

DevOps, and Marketplace Customizations/Integrations (Shopify, Amazon, Ebay, BigCommerce). Odoo Consultant and Developer. Expertise in Emerging Technologies: * Automation & DevOps: Streamline operations with Docker, AWS, Google Cloud. * Expertise in CI/CD pipelines, server management, and infrastructure as code. * Data Analysis & Machine Learning: Advanced skills in Python for data analysis, modeling, and machine learning, leveraging a dissertation project in this field. Skilled in creating actionable insights from complex datasets. * AI-Powered Solutions: Integrating AI tools and APIs to enhance user experiences, automate workflows, and improve performance in e-commerce platforms. Odoo Consultant and Developer: Extensive experience as a consultant and developer with the Odoo ERP platform, specializing in creating custom modules tailored to specific business requirements, seamless integration with external systems (including CRM, accounting, and inventory management). Marketplace Development Specialist: * Shopify Expert: Store setup, advanced customizations, app development, SEO optimization, liquid template customizations, and platform migrations. * Amazon & eBay Integrations: Proficient with Amazon MWS, SP API, Advertising API, eBay API, and BigCommerce API for seamless integrations and automation. Tech Stack Highlights: * Backend: Java / Spring Boot / Node.js / Python * Frontend: Vue.js / React.js * Mobile Development: React Native (iOS & Android) * DevOps Tools: Docker / AWS / Google Cloud / CI/CD Pipelines * Machine Learning: Python (NumPy, Pandas, scikit-learn, TensorFlow) * Database: MongoDB / SQL / Data Pipelines * Scripting: Bash / Shell Scripts / OAuth Integration Why Choose Me? I bring over 20+ years of experience as a Computer Science Engineer, blending expertise in software development. My passion lies in leveraging the latest technologies to solve complex challenges and drive measurable results for clients. I have a degree in Computer Sciences.

Need someone who can build, stabilize and scale your Android product? You found him 🤝 📊 12+ years in mobile delivery 📊 20+ Android-focused projects 📊 10+ years with regulated and business-critical products 📊 30+ production Android release cycles 📊 5+ years in Kotlin-first development 📊 4 product areas: compliance-ready apps, secure payments, backend-heavy systems and Software Development I help companies build secure, maintainable apps Healthcare, FinTech, consumer products. Core Expertise 🔹 Native Android engineering with modern architecture and Software Design 🔹 Kotlin-first development for maintainability 🔹 Legacy modernization 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 reliability and clean architecture. 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 as ai mobile app developer ✅ 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 My strongest specialization is android developer kotlin work. I join teams that need android developer kotlin java skills to modernize legacy code, migrate modules, and improve release quality without a full rewrite. That benefits from practical experience as a java developer from thinking like an android kotlin developer who can handle new features and stabilization. Relevant Experience Highlights as a full stack mobile app developer 🔸 Healthcare mobile applications with compliance-aware architecture 🔸 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, full stack developer 🔸 Ability to scale from one engineer to a delivery team I also have experience with android ble, android bluetooth features for pairing flows, 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, ai mobile app development. Tech Stack 🔸 Android kotlin with Jetpack, Compose, Android SDK, AOSP 🔸 Java, Firebase, secure cloud services, CI/CD 🔸 REST APIs, secure auth, payment gateways, mobile app development api 🔸 Node.js, JavaScript, C#, SQL 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 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.