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✅ 8+ Years of Java Development Experience ⚡ Full-Cycle Backend Development & Architecture ⚡ AI-Powered Development for Faster Delivery & Better Code Quality 👀 Click Invite or Hire for Scalable Java Backend Solutions Looking for a Java Developer who can build scalable backend systems, SaaS platforms, enterprise applications, and cloud-native solutions designed for long-term growth? For 8+ years, I have helped startups, SaaS companies, fintech businesses, AdTech platforms, and enterprise organizations build secure, scalable, and high-performance software using Java, Spring Boot, PostgreSQL, MySQL, Kafka, GraphQL, AWS, Docker, Kubernetes, and modern cloud technologies. From backend architecture and microservices development to legacy application modernization, API integrations, troubleshooting, cloud deployments, and AI-assisted engineering, I deliver production-ready solutions built to scale. 👉 WHAT YOU GET: ✔️ Java Backend Development & Software Architecture ✔️ Spring Boot Applications & Microservices ✔️ REST APIs, GraphQL APIs & Integrations ✔️ Cloud-Native Applications using AWS ✔️ AI-Assisted Development & Automation ✔️ Legacy System Modernization ✔️ Long-Term Support, Maintenance & Optimization 🏆 KEY ACHIEVEMENTS: ✔️ 8+ years building Java, Spring Boot, and enterprise backend applications ✔️ Built scalable SaaS platforms, fintech applications, AdTech systems, and enterprise software ✔️ Maintained and enhanced 15+ production microservices ✔️ Contributed to Adstrome, TrustArc, Acquia DAM, and Digi-Docket ✔️ Designed secure APIs, event-driven systems, and scalable architectures ✔️ Improved application performance through optimization and modernization ⚙️ CORE EXPERTISE: ✔️ Java, Core Java, Java EE, Spring Boot, Spring MVC, Spring Security ✔️ Hibernate, JPA, JDBC, MyBatis, ORM Frameworks, REST APIs, GraphQL APIs ✔️ Microservices Architecture, Apache Kafka, Event-Driven Systems ✔️ PostgreSQL, MySQL, Snowflake, Query Optimization ✔️ AWS, Docker, Kubernetes, Jenkins, Maven, Gradle, Git, GitHub, Bitbucket, Version Control Systems ✔️ Authentication, Authorization, RBAC, Multi-Tenant SaaS ✔️ ZK Framework & Enterprise Web Application Development 🛠 DEVELOPMENT & MAINTENANCE: ✔️ Web Application Development & Enterprise Software Development ✔️ Spring MVC & ZK Framework Application Development ✔️ Legacy Application Maintenance, Modernization & Application Upgrades ✔️ Feature Development & Application Enhancements ✔️ Bug Fixing, Root Cause Analysis & Production Support ✔️ Performance Bottleneck Analysis & Optimization ✔️ Memory Leak Detection & Resolution ✔️ Security Vulnerability & CVE Remediation ✔️ Third-Party API Integration & Business Workflow Automation ✔️ Performance Optimization & Scalability Improvements ☁️ CLOUD & DEVOPS: ✔️ AWS Cloud Services, Docker Containerization & Containerized Application Deployment ✔️ Kubernetes Container Orchestration for Scalable Cloud Infrastructure ✔️ Linux-Based Server Systems, Linux Server Administration & Linux Server Troubleshooting ✔️ Apache Tomcat Installation, Deployment, Monitoring & Performance Tuning ✔️ CI/CD Pipelines, Jenkins Automation, Git, GitHub, Bitbucket & Version Control Systems ✔️ Web Application Troubleshooting, Production Environment Support & Incident Resolution 🧪 TESTING & QUALITY: ✔️ JUnit, Mockito, Unit Testing & Integration Testing ✔️ Test-Driven Development & Automated Testing ✔️ API Testing, Debugging & Log Analysis ✔️ Root Cause Investigation & Production Stability ✔️ Code Quality Improvements & Maintainable Software Development ✔️ Regression Testing & Application Reliability Improvements 🤖 AI-ENHANCED ENGINEERING: ✔️ AI-Assisted Development & AI-Powered Coding Workflows ✔️ OpenAI API Integration, LLM Workflows & AI Automation ✔️ AI-Assisted Testing, Refactoring & Documentation ✔️ Faster Delivery Through AI-Enhanced Engineering 🏢 INDUSTRY EXPERIENCE: ✔️ SaaS Platforms & Enterprise Applications ✔️ AdTech & Programmatic Advertising ✔️ Fintech & Loan Processing ✔️ Privacy & Compliance Systems ✔️ Digital Asset Management ✔️ Multi-Tenant & White-Label Solutions 🚀 WHY CLIENTS CHOOSE ME: ✔️ 8+ Years of Java Development Experience ✔️ Enterprise SaaS & Microservices Expertise ✔️ Strong Spring Boot & Cloud-Native Skills ✔️ Scalable, Secure & Maintainable Solutions Whether you need to build a backend platform from scratch, scale an existing SaaS application, maintain a legacy system, resolve performance bottlenecks, remediate security vulnerabilities, implement microservices, modernize enterprise software, deploy applications on Tomcat or Linux-based server systems, integrate AI capabilities, or optimize application performance, I can help. Looking for a Java Developer, Senior Java Developer, Java Backend Developer, Spring Boot Developer, Java Architect, Backend Engineer, Enterprise Software Developer, API Developer, GraphQL Developer, AWS Developer, Cloud Engineer, Kafka Developer, Software Architect, Backend Architect, or Java Consultant?

Senior Full-Stack Java | Spring Boot | AWS | React | AI Integration | Security Hello! I'm Deepak Kumar, a Senior Software Engineer and Full-Stack Developer with 8+ years of professional experience building scalable backend systems, cloud-native applications, APIs, and modern web applications. I specialize in Java, Spring Boot, Spring Security, React, AWS, microservices, and cloud-native development, with a strong focus on building secure, reliable, high-performance applications. After several years away from Upwork, I'm now actively returning to the platform and focusing on helping businesses build and modernize their software using modern Java/Spring technologies, cloud platforms, AI integrations, and secure full-stack architectures. 🚀 What I Can Help You Build Enterprise Java & Spring Boot applications RESTful APIs and microservices Secure applications with Spring Security OAuth 2.0, OpenID Connect, JWT and SSO React-based web applications and dashboards AWS cloud-native applications Docker & Kubernetes deployments CI/CD pipelines and DevOps automation AI/LLM integrations into existing applications AI-powered features, APIs and automation Database design and optimization High-performance and highly scalable systems Legacy application modernization Third-party API integrations Real-time applications using WebSockets Event-driven architectures with Kafka, Kinesis, RabbitMQ, etc. 💻 Core Technology Stack Backend Java 8/11+ Spring Boot Spring Framework Spring Data Spring Security Hibernate / JPA REST APIs Microservices WebSockets SOAP / Web Services Frontend React JavaScript HTML5 / CSS3 Bootstrap Thymeleaf Security Spring Security OAuth 2.0 OpenID Connect JWT SSO LDAP / CAS Role-based access control API security Cloud & DevOps AWS Google Cloud Platform (GCP) Docker Kubernetes ECS Lambda API Gateway CloudFront Route 53 SQS / SNS DynamoDB S3 Athena Redshift Aurora CI/CD Jenkins Bamboo CircleCI SonarQube Databases PostgreSQL Oracle MySQL MongoDB Cassandra Redis DynamoDB Redshift Athena / S3 Messaging & Streaming Apache Kafka AWS Kinesis RabbitMQ Apache Camel Event-driven architectures 🤖 AI & Modern Application Development I'm particularly interested in helping companies bring AI capabilities into existing Java/Spring applications rather than rebuilding everything from scratch. Examples include: Integrating LLM/AI APIs with Spring Boot AI-powered REST APIs Intelligent search and document processing AI assistants and chat functionality RAG-based application architectures Connecting AI services with existing enterprise systems AI workflow automation Secure AI integrations Building React interfaces for AI-powered applications ⚡ Performance & Reliability I also have experience analyzing and improving application performance using tools such as: JMeter JProfiler AWS X-Ray Gatling GTMetrix I focus on identifying bottlenecks across the application, database, API, infrastructure, and cloud layers rather than treating performance problems at only the code level. ⭐ Why Work With Me? Quality First: I focus on writing maintainable, production-ready code rather than simply making something work. Problem Solving: I enjoy debugging complex problems, understanding the root cause, and designing practical solutions. Clear Communication: I believe good communication is just as important as good code. I keep clients informed about progress, challenges, and technical decisions. Security Mindset: Security is considered from the architecture and API design stage, not added as an afterthought. Cloud & Scalability: I can work across application and infrastructure layers, from Spring Boot services all the way to AWS deployment and scaling. Business-Focused: My goal isn't just to deliver code. It's to understand what you're trying to achieve and build a solution that provides real business value. 🔧 Looking for help with Java, Spring Boot, AWS, React or AI? Whether you're building a new application, modernizing a legacy Java system, securing APIs, migrating to the cloud, improving performance, or adding AI capabilities to an existing product, I'd be happy to discuss your requirements. Let's build something reliable, secure, scalable, and future-ready.

I’m a Senior Java Backend Engineer with over 14 years of experience building mission-critical systems in fintech, with a strong focus on payments, lending platforms, and core banking solutions. I specialize in Java and Spring Boot, and design backend systems that are secure, scalable, and capable of handling high-volume financial transactions with consistency and reliability. I’ve worked on systems involving payment processing, transaction workflows, loan management, and integrations with external financial services and APIs. This includes designing and building robust microservices architectures that support real-time and asynchronous processing, ensuring data accuracy, fault tolerance, and seamless service communication. I understand the importance of idempotency, transaction integrity, and failure handling in financial systems where even minor inconsistencies can have significant impact. Security and compliance are central to my approach. I have strong experience implementing secure authentication and authorization using Spring Security, token-based systems, and role-based access control. I build APIs and backend services that align with financial industry expectations around data protection, auditability, and reliability. From a technical standpoint, I bring deep expertise in Spring Boot, microservices, REST API design, JPA/Hibernate, and relational databases like MySQL and PostgreSQL. I’m comfortable designing systems from scratch as well as improving and scaling existing platforms, optimizing performance, and ensuring stability under load. I also have hands-on experience with AWS and Google Cloud, and have worked on deploying and managing backend systems in cloud environments. I understand how to design cloud-ready architectures, implement CI/CD pipelines, and ensure systems are resilient, observable, and production-ready. What sets me apart is my ability to think beyond just implementation. In fintech systems, correctness, reliability, and long-term maintainability matter more than quick fixes. I focus on building clean, well-structured systems that not only meet current requirements but are also prepared for future scale, regulatory needs, and product evolution. If you’re building or scaling a payments platform, lending system, or core banking backend and need someone who understands both the technical and domain challenges, I’d be glad to contribute.

Greetings! I'm Abhishek, a Sr. Software Engineer with 15+ years of experience as a Full Stack Developer and 9+ years as a Cloud Engineer. Technology Stack Details: ✓ Java: Java (7,8,11), SpringBoot, Spring Data, Spring Rest, Spring Cloud, JavaEE, Hibernate ✓ Cloud: AWS, Google Cloud (GCP), Docker, Kubernetes, ECS, Cloud-native apps, scalable clusters, zero-downtime deployment. ✓ Databases: Oracle/PostgreSQL/MySQL, big volume storage (AWS Redshift, AWS Athena/S3, Aurora, Cassandra, HDFS), Redis, MongoDB. ✓ Security: OAuth2, OpenID Connect, JWT, SSO-Single Sign-On, CAS / LDAP ✓ Web: Bootstrap, React, Thymleaf, JavaScript, OAuth, Tomcat, Nginx. ✓ API integrations: REST, SOAP, WebServices, WebSockets, etc. ✓ AWS: Clusters, Kinesis, Athena, Redshift, DynamoDB, Lambda, IoT, SQS/SNS, CloudFront/Route53/ApiGateway, vast AWS API usage, and automation. ✓ Data streaming: AWS Kinesis, Kafka, Camel, RabbitMQ. ✓ Performance optimization: JMeter, JProfiler, AWS X-Ray, GTMetrix, Gatling. ✓ CI/CD: Bamboo, Jenkins, Circle CI, Sonar, pipelines. ✓ Others: Maven, Gradle, Swagger, Linux, Git. 🌟 WHY CHOOSE ME OVER OTHER FREELANCERS? 🌟 ✅ Client Reviews: I focus on providing VALUE to all of my Clients and Earning their TRUST. The Client Reviews and Feedback on my Profile are immensely important to me and the value that I provide. ✅ Over-Delivering: This is core to my work as a Freelancer. My focus is on GIVING more than what I expect to RECEIVE. I take pride in leaving all of my Clients saying "WOW" ✅ Responsiveness: Being extremely responsive and keeping all lines of communication readily open with my Clients. ✅ Resilience: Reach out to any of my Current of Former Clients and ask them about my Resilience. Any issue that my Clients face, I attack them and find a SOLUTION. ✅ Kindness: One of the biggest aspects of my life that I implement in every facet of my life. Treating everyone with respect, understanding all situations, and genuinely wanting to IMPROVE my Client's situations. I am eager to work with you, to provide reliable, consistent, and High-Level solutions to design/development challenges. Please contact me, so we can discuss how we can work together to FULLY meet your Business Needs!

Top Rated on Upwork | 100% Job Success Score | 18+ clients served I design and build backend systems that handle real production loads — scalable microservices, high-throughput REST APIs, and cloud-native Java architectures engineered for reliability and growth. I bring experience working on production-grade applications at SmartBear, building systems used in real-world environments with a strong focus on performance, scalability, and reliability. What I can help you with: 🔹 Scalable backend development — Java, Spring Boot, Microservices 🔹 REST API design, third-party integrations & payment gateways 🔹 Performance optimization — reduce latency, improve query speed & scalability 🔹 Microservices architecture & system design 🔹 CI/CD setup, Docker, code quality & API efficiency Core Technologies: 🔹 Backend — Java, Spring, Python 🔹 Databases — MySQL, PostgreSQL, MongoDB, Redis 🔹 Cloud & Deployment — AWS (EC2, S3, Lambda, RDS), Docker, CI/CD Every system I build is designed to be maintainable, scalable, and production-ready from day one. If you need a backend engineer who delivers results — let's talk.

⭐⭐⭐⭐⭐ Delivering scalable, high-performance applications that are built to grow with your business. I am a Senior Java Full Stack Developer with 10+ years of experience building enterprise-grade backend systems, web applications, and scalable platforms across fintech, telecom, SaaS, healthcare, and operational domains. I specialize in Java, Spring Boot, Microservices, REST APIs, React.js, PostgreSQL, Kafka, and cloud-native architectures, with a strong focus on performance, maintainability, and clean system design. I have contributed to large-scale production systems for organizations such as Paytm and Airtel Africa, helping teams build reliable applications that serve thousands of users and business-critical operations. Core Expertise Backend Development • Java, Core Java • Spring Boot, Spring Framework • Hibernate, JPA , Kubernetes • REST API Development • Microservices Architecture • Kafka • WebSphere • Docker Frontend Development • React.js • Next.js • JavaScript • HTML5 • CSS3 • Tailwind CSS Databases • PostgreSQL • MySQL • MongoDB • SQLite Architecture & Integrations • Scalable System Design • API Integrations • Authentication & Authorization • Payment Gateway Integrations • Notification Systems • Third Party Service Integrations • Performance Optimization AI Assisted Development & Productivity • ChatGPT • Claude • GitHub Copilot • Cursor AI • AI Assisted Code Generation • AI Powered Debugging & Refactoring • Rapid Prototyping & Development Acceleration • AI Enhanced Documentation & Code Reviews What I Bring to Your Project ✅ Clean, maintainable, production-ready code ✅ Strong problem-solving and debugging skills ✅ Clear communication and reliable delivery ✅ Experience working in Agile development environments ✅ Effective use of AI tools to accelerate development while maintaining code quality ✅ Focus on scalability, performance, and long-term maintainability Whether you need a Spring Boot backend, React frontend, REST API development, microservices implementation, system optimization, AI assisted development, or full stack application development, I can help turn your requirements into reliable, scalable solutions. Let's discuss your project and find the best approach to achieve your goals efficiently.