I help businesses build, scale, and modernize enterprise portal and backend solutions using Liferay DXP, Spring Boot, and Java and integrate AI capabilities that make those platforms smarter and more automated. 100% Job Success Score. Top Rated. 15 completed projects. 7,800+ hours delivered. I don't just write code. I architect solutions that last. ★★ Why Clients Choose Me ★★ ✔ End-to-end ownership from requirement analysis to deployment and maintenance ✔ Clean, modular, well-documented code built for long-term maintainability ✔ Experienced as Developer, Architect, and Team Lead in agile environments ✔ Strong communicator who keeps projects on track and clients informed ✔ Equally effective working independently or leading a team 🤖 AI & Modern Integration Clients increasingly need AI built into their existing systems not as a separate tool, but woven into their portals, workflows, and APIs. I deliver that: ✦ LLM Integration: OpenAI (GPT-4o), Claude (Anthropic), Google Gemini via REST APIs ✦ RAG Pipelines: context-aware AI assistants using LangChain, LlamaIndex, and vector databases (Pinecone, Weaviate, pgvector) ✦ AI-Powered Search: semantic search and intelligent recommendations via Elasticsearch + embeddings ✦ Workflow Automation: integrating AI into Spring Boot microservices for document processing, classification, and business automation ✦ Chatbot Development: intelligent support and internal bots for enterprise portals ✦ Prompt Engineering: production-safe, reliable prompt design for real business use cases ☕ Java / Spring Boot ✦ Spring Boot 3.x, Spring Framework 5.x, Spring Security, Spring Data JPA ✦ Microservices architecture, REST & SOAP APIs ✦ RabbitMQ, Kafka for async messaging ✦ Hibernate/JPA, Maven, Gradle ✦ Databases: MySQL, PostgreSQL, Oracle, MongoDB, Cassandra 🌐 Liferay DXP Expertise With deep hands-on experience across Liferay 5.x through 7.x/DXP, I cover the full lifecycle: ✦ Portlet, Hook, Theme, and Extension development ✦ Liferay DXP environment setup, performance tuning, and clustering ✦ SSO integration, LDAP, CAS, Keycloak ✦ Elasticsearch integration and workflow management ✦ Version migrations and upgrades (5.x → 6.x → 7.x/DXP) ✦ Payment gateway integration (Stripe, Authorize.net, BillDesk) ✦ Content management and enterprise portal solutions ☁️ DevOps & Cloud ✦ AWS (EC2, S3, Lambda, RDS) ✦ Kubernetes, Docker, Jenkins CI/CD ✦ Cloud Foundry ✦ Git, SVN. version control and branching strategies ✦ Splunk monitoring with DB Connect and Active Directory LDAP 📱 Android Development (Java & Kotlin) ✦ REST/SOAP web services, JSON/XML parsing ✦ Messaging: Twilio, XMPP, QuickBlox, OpenFire ✦ Social integrations: Spotify, Facebook, Instagram, SoundCloud ✦ Maps: Google Maps, Mapbox, GPS ✦ Payments: Stripe, Authorize.net, BillDesk 🛠 Full Tech Stack Languages: Java, Kotlin, JavaScript, TypeScript Frameworks: Spring Boot, Hibernate, React.js, Angular AI/ML: LangChain, OpenAI API, Claude API, vector databases, RAG pipelines Cloud: AWS, Kubernetes, Jenkins, Cloud Foundry Databases: MySQL, PostgreSQL, Oracle, MongoDB, Cassandra Tools: Git, Maven, Gradle, Eclipse, JIRA 📌 Notable Projects ✦ Built a music social network with stories, followers, and deep API integrations Spotify, Apple Music, YouTube, Facebook, Instagram ✦ Led a cross-functional agile team across native and backend development, reporting directly to product executives ✦ Architected and delivered enterprise portal solutions for large organizations on Liferay DXP ✦ Implemented Splunk enterprise monitoring with DB Connect and Active Directory LDAP ✦ Delivered full-stack AI integration projects connecting LLMs to existing Java/Spring Boot backends Let's talk about your project. Whether you need a robust backend API, a Liferay portal built or migrated, or an AI feature integrated into your existing system, I deliver on time, with clear communication throughout. Message me and let's get started.

Hi there 👋 I am a senior full-stack software developer with over 5 years of experience, I am proficient in Java, Golang, TypeScript, React, Vue, Node, MySql, and MongoDB. I strive to write high quality code and build scalable and maintainable infrastructure.🎯 I enjoy contributing to OSS, embarking on new challenges and build awesome projects. Please feel free to contact me.😁

🏅 Top Rated Freelancer | ✅ 100% Job Success | ⭐ 5-Star Rating | 📈 11+ Years of Experience Having 11+ years of experience in Java Fullstack Development. Having strong knowledge of building Modern REST APIs, Microservice architecture, Containerization using Docker, and technologies like Kubernetes, and Cloud Native application development. Here is my full technical background. I am good at: ✔ Spring MVC, Spring Hibernate/JPA, Spring REST, Spring Boot & Spring Security ✔ Maven, Git, Jira ✔ Core Java, J2EE, JSP and Servlet ✔ Microservice architecture ✔ DevOps tools like Docker, Github CI/CD, Kubernetes, Datadog, AWS Roles and Responsibilities held: ✔ Worked extensively on Microservice architecture based web-applications using Hibernate, JPA, and different modules of Spring Frameworks like Spring Boot, Spring REST, Spring Security, Spring MVC, and Spring AOP. ✔ Solid knowledge in writing user-defined database functions, Store Procedures, Cursors, Views, and SQL queries, and also involved in creating and deciding the DB schema of my modules. ✔ Solid knowledge of SQL DBs like MySQL, MS SQL, Postgres, Oracle, and NoSQL DBs like ElasticSearch, MongoDB, etc. ✔ Having experience working in a production environment and resolving client issues during production hours. ✔ Use SCRUM for agile development and participated in team-led solutions, reviewing peer code for quality and completeness.

🎯 𝗙𝗿𝗮𝗰𝘁𝗶𝗼𝗻𝗮𝗹 𝗖𝗧𝗢 & 𝗔𝗜 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁 · 𝟭𝟱+ 𝗬𝗲𝗮𝗿𝘀 · 𝟵,𝟭𝟬𝟬+ 𝗨𝗽𝘄𝗼𝗿𝗸 𝗛𝗼𝘂𝗿𝘀 · 𝟭𝟬𝟬% 𝗝𝗦𝗦. I architect and ship AI products. Java, Python, LLM and RAG systems, AI agents, full-stack, and a senior team that builds 100% of your spec. I am 𝐆𝐮𝐦𝐚𝐧𝐬𝐢𝐧𝐡. For 15+ years I have built software, led delivery, and sat on the buying side of IT services, and today I work as a Fractional CTO and AI Architect for founders who are betting their company on getting the technology right. Here is the deal I make with every client. You stay in the driver's seat. I run the machine. I sit with you through onboarding, turn what is in your head into a written plan and a real architecture, and then a senior engineering team I lead builds it, ten out of ten, against that exact plan. Nothing is called done until it matches what we agreed. I have closed twelve contracts on Upwork this way. Every one is five-star. 100% Job Success. Zero exceptions in over four years. 🔶 𝗪𝗛𝗔𝗧 𝗜 𝗔𝗖𝗧𝗨𝗔𝗟𝗟𝗬 𝗗𝗢 I am most useful when there is real AI in the build and a business riding on it. ✵ AI architecture and engineering : LLM applications on GPT-4o and Claude, retrieval-augmented generation on pgvector, Pinecone, and Qdrant, AI agents and multi-agent orchestration with LangGraph and the Model Context Protocol, evaluation harnesses so you can measure accuracy instead of hoping, and guardrails against prompt injection and hallucination inside a regulated boundary. I have shipped a clinical compliance agent that reads policy and unstructured notes, returns structured answers, and logs every decision for audit. Production AI, with the deterministic validators that keep a model honest. Not a demo. ✵ Java and Python backends : Enterprise Java and Spring Boot for the system of record. Python and FastAPI for the model, data, and orchestration layer. Microservices, event-driven design, REST and gRPC, Postgres, Kafka, Redis, and AWS underneath it all. This is the plumbing that turns an AI prototype into something a real company can run. ✵ Fractional CTO leadership : I plug in as the technology executive your stage cannot yet hire full-time. Architecture decisions, the roadmap, build versus buy, hiring the right engineers, code-quality bars, vendor and agency oversight, and technical due diligence for your next raise. I have done this for Series A and Series B founders and co-presented the technical story in their investor rooms. ✵ Full-stack and ecommerce : where it serves the product. React and Next.js front ends, Ruby on Rails SaaS, Shopify Plus and headless storefronts, Salesforce and CRM integration. I do not lead with this, but when an AI product needs a real interface and a real checkout, my team builds that too. 🔶 𝗛𝗢𝗪 𝗪𝗘 𝗪𝗢𝗥𝗞 𝗧𝗢𝗚𝗘𝗧𝗛𝗘𝗥 You and I own the relationship. I run your onboarding, capture every requirement in writing, set the architecture, and stay your single point of contact start to finish. Behind me is a hand-picked senior team, ten-plus years each on their stack, who write the code under my direction. This is not staff augmentation and it is not an offshore center handed your repo. I am in the code with them, reviewing pull requests and architecture, which is the direction most contractors are missing and the reason you stop paying for rewrites. The promise is simple and I put it in writing on day one. We agree what done looks like before anyone writes a line, against acceptance criteria we can both measure. We build to that list. Everything ships to a staging URL for your sign-off before it counts. You get a written update on the days we work. Nothing is marked complete until it matches the spec, exactly. That is what I mean by ten out of ten on your requirements. 🔶 𝗪𝗛𝗬 𝗙𝗢𝗨𝗡𝗗𝗘𝗥𝗦 𝗧𝗥𝗨𝗦𝗧 𝗠𝗘 "Our client treated him as his own CTO, not an external employee. He built an AI-powered roadmap that reduced manual effort and gave them a real competitive advantage." (Bharat, Founder, Fourfold Tech) "Outstanding professionalism, deep expertise, delivering high-quality results on time." (Healthcare SaaS, 4,409 hrs) "Exceptional knowledge and dedication, consistently delivering results as requested." (Healthcare SaaS, 3,848 hrs) 🔶 𝗕𝗘𝗦𝗧 𝗙𝗜𝗧 AI and SaaS founders who need a Fractional CTO without giving up equity. Teams putting real AI into production under HIPAA, SOC2, or fintech rules. Founders who need an MVP architected right the first time. Operators modernizing a Java or legacy system to clean services on AWS. Engagements from $15K to $500K-plus. Tell me what you have now and what you need next, in a couple of sentences. I will come back with a plan, a timeline, and a milestone or retainer proposal within two hours on business days. 𝐆𝐮𝐦𝐚𝐧𝐬𝐢𝐧𝐡.

Greetings! I'm Robert Kiprotich, a seasoned Principal Software Engineer with over ten years of hands-on experience designing and implementing cutting-edge software solutions. My expertise lies in Java, Spring Boot, ReactJS, and Python programming languages and frameworks, and I thrive on tackling complex challenges to deliver robust and scalable software. Why Choose Me? ✅ Leadership and Innovation: As a Principal Software Engineer, I have successfully led teams in developing and deploying software solutions that drive business growth. My strategic mindset and innovative approach ensure your project stays ahead in the rapidly evolving tech landscape. ✅ Full-Stack Proficiency: I am well-versed in both front-end and back-end development, allowing me to create seamless, end-to-end solutions. From crafting responsive user interfaces to optimizing server-side performance, I bring a holistic perspective to software development. ✅ Architecture Design: My strength lies in designing scalable and maintainable architectures. I am adept at creating robust systems that can handle high loads, ensuring your application remains performant even as user numbers grow. ✅ Collaborative Team Player: I understand the importance of effective communication and collaboration. Whether working with a remote team or directly with stakeholders, I prioritize transparent communication to ensure everyone is on the same page throughout the development lifecycle. My Technical Toolkit: Languages: Java, ReactJS, Javascript, Python Frameworks: Spring Boot, Django Tools: Visual Studio Code, IntelliJ, Eclipse, Jenkins Previous Success Stories: I successfully led the development of an airtime loaning system. Implemented using Java Spring Boot Microservice architecture resulting in stable high throughput application handling over one million transactions per day. Let's Transform Your Vision into Reality: I am excited about the prospect of bringing my skills to your project. Whether you're looking to build a new application, optimize an existing system, or need strategic guidance, I am ready to contribute to your success. Let's discuss how we can collaborate to achieve your goals. Feel free to reach out, and let's start the journey towards a successful project!

Software Engineer | Java & Spring Boot Back-End Developer I am a highly motivated Junior Software Engineer specializing in the Java/Spring ecosystem, dedicated to building robust and scalable back-end applications. Core Strengths & Technical Expertise: Java Back-End Mastery: Solid skills in designing and developing reliable API RESTful applications using modern frameworks, including Java, Spring Boot, and Spring Security. Full-Stack Versatility: Experienced with key front-end technologies (JavaScript, React) and a first professional background in web development using PHP and WordPress. Data & Tools: Proficient in database management (SQL, PostgreSQL, MySQL) and industry-standard development tools (Git, GitHub, IntelliJ IDEA). I am actively seeking challenging Java development opportunities to apply and deepen my technical skills within a professional setting. Let's collaborate to bring your project to life!

Senior Java Fullstack Developer with 6+ years of experience building scalable, cloud-native enterprise systems using Spring Boot, React, Angular, Microservices, and AWS. I specialize in: - Java/Spring Boot backend development & REST API design - Microservices architecture with Docker & Kubernetes - Cloud deployment on AWS (EC2, S3, Lambda, RDS) - Frontend development using React, Redux, Angular, TypeScript - Database optimization (PostgreSQL, MySQL, MsSQL, Oracle, Sybase, MongoDB, Apache Solr, Redis, Elasticsearch, DynamoDB) - Event-driven systems with Apache Kafka & RabbitMQ - CI/CD pipelines with Jenkins, Maven & Git Projects I've delivered include real-time analytics platforms, fintech payment systems, e-commerce backends, and enterprise SaaS applications — all built for high availability and performance at scale. Top Rated Plus on Upwork (Top 3%) | 100% Job Success | Toptal Qualified (Top 3% Global Talent) If you need a reliable Java developer to architect and deliver production-ready backend systems, let's connect.

Proven expertise in managing the entire software development lifecycle—from gathering customer requirements, analysis, and design to development, automated testing, and deployment—utilizing a diverse technology stack including Java/J2EE, Python, C#, VueJS, AngularJS, JSF/PrimeFaces, Laravel, PHP, AWS, and WordPress. Extensive experience in the design and development of mission-critical applications, with a strong focus on: Requirement Analysis: Collaborating with stakeholders to understand and document project requirements, ensuring alignment with business objectives. Technical Design: Crafting robust architectural solutions, creating proof of concepts (POC), and providing detailed estimations to guide project execution. Development & Automation: Leading development teams to implement scalable, high-performance applications, and utilizing automation tools for testing and deployment. Code Review & DevOps: Conducting thorough code reviews to maintain quality standards and driving continuous integration and deployment processes using DevOps best practices. Skilled in providing comprehensive support for critical applications, offering clients in-depth technical knowledge, customized solutions, and feature-specific enhancements. A quick learner with a demonstrated ability to adapt to rapidly changing technical environments and resolve complex issues effectively. Known for delivering high-quality results under tight deadlines. Technical Skills/Tools: Programming Languages & Frameworks: Java, J2EE, Python, C#, PHP, Laravel JSF, PrimeFaces, Spring, Spring Boot VueJS, AngularJS, JavaScript, NodeJS Web Development: WordPress, HTML/JS/JSON Version Control & CI/CD: Git, SVN, Maven, Jenkins, Docker, Ansible Other Tools: Eclipse IDE, Trello Specializations: Machine Learning, AI, Selenium (Java), Data Scraping Tools (Java) Unity

• 5+ years of experience as a Mobile App Developer specializing as an Android Developer and Flutter Developer. • Strong expertise as a Mobile App Developer with deep knowledge of Android Kotlin, Java, and Dart. • Proven background as an Android Developer and Flutter Developer across FinTech, AdTech, and EdTech projects. • Hands-on experience as a Mobile App Developer integrating third-party APIs for scalable applications. • Solid architectural mindset as an Android Developer focused on performance and UX. Are you looking for a reliable Mobile App Developer who can also act as a senior Android Developer or an experienced Flutter Developer? 🚀 I bring extensive hands-on expertise as a Mobile App Developer, delivering high-quality solutions as both an Android Developer and Flutter Developer. Whether you need a native Android solution or a cross-platform app, I’m ready to help. 📱 Android Developer Expertise As an Android Developer, I’ve delivered multiple production-ready applications with a focus on scalability and clean architecture. My experience as a Mobile App Developer allows me to approach Android development from both technical and product perspectives. Android Toolkit (Android Developer focus): • Java & Kotlin — core stack of every Android Developer project • XML, Material Design, Jetpack Compose — essential tools for any Android Developer • SQLite & Room — data handling by an experienced Mobile App Developer • Retrofit, OkHttp, Gson — API integration as a professional Android Developer • Dagger & Hilt — clean architecture every Android Developer should follow • Coroutines & Flow — asynchronous programming mastered by a senior Mobile App Developer Each app I build as an Android Developer meets high standards of performance and maintainability. 🌐 Flutter Developer Mastery As a Flutter Developer, I build fast, consistent cross-platform applications with a native feel. My role as a Mobile App Developer helps ensure business logic and UI remain aligned across platforms. Flutter Toolkit (Flutter Developer focus): • Dart & FlutterFlow — core stack of every Flutter Developer • Firebase Auth, Google & Apple Sign-In — secure solutions from a Flutter Developer • Google Maps API — location-based features by an experienced Mobile App Developer • Firebase Cloud Messaging — real-time updates from a senior Flutter Developer • BLoC & Riverpod — scalable state management used by every strong Flutter Developer Whether it’s CRM, LMS, or EdTech, I deliver results as a Flutter Developer with product thinking. 🏗️ Architecture & Best Practices As a Mobile App Developer, I apply proven patterns: • MVP, MVC, MVVM, MVI — standard for every Android Developer • BLoC & Riverpod — best choice for a scalable Flutter Developer workflow Clean architecture is a must for any professional Mobile App Developer. 🔒 Security & Performance Every Mobile App Developer project I deliver focuses on: • Data encryption • Performance optimization • GitHub, GitLab, Azure workflows This mindset separates a senior Android Developer and Flutter Developer from the rest. 💻 Databases & Experimentation As a versatile Mobile App Developer, I work with: • SQLite • PostgreSQL • Firebase I continuously experiment to grow as an Android Developer and Flutter Developer. 🎯 Let’s Build Your App If you need a results-driven Mobile App Developer, a reliable Android Developer, or a skilled Flutter Developer — let’s connect and turn your idea into a production-ready application.

Tight Deadline? I Deliver. | 100% Job Success | 14+ Yrs Experience | Free 15-min Consult I’m an experienced Full Stack Developer with 7+ years in building scalable, high-performance web and SaaS solutions. I focus on delivering clean architecture, reliable systems, and long-term client partnerships. Tech Stack: Node.js | Shopify | Electron.js | Angular.js | React.js (Redux, Firebase, Material UI, SCSS, SASS, GraphQL, Apollo) | Front-End UI Libraries (Semantic, Material, Ant Design, Bootstrap) | Java | Core Java | Spring Boot | Play Framework | Hibernate | Scala | .NET, .NET Core | Entity Framework | AWS (AppSync, Amplify, Lambda, Cognito, S3, SES, IAM, EC2) | Azure (Cosmos DB, DevOps, Data Migration, EventHubs) | API Gateway | Databases (MongoDB, SQL Server, MySQL, PostgreSQL) Integrations: PayPal | Stripe | Twilio | MailChimp | Google Play Services | 2Checkout | QuickBooks Data Migration: Data Import/Export | Data Loader | ETL Tools (Pentaho) Let’s build something elegant, intelligent, and fast. → Book your free 15-minute consultation today.