You will get Upgrade Your Legacy Java Application to Java 21 Safely
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Project details
Upgrade your legacy Java application safely to Java 21 with minimal disruption and maximum compatibility. With 7+ years of experience building and maintaining enterprise-grade Java applications, SaaS platforms, microservices, and production systems, I help businesses modernize their codebase while preserving stability and performance.
This service includes Java version migration, dependency compatibility review, build configuration updates, code refactoring where required, issue resolution, testing support, and deployment readiness validation.
Whether your application is built using plain Java, Spring Framework, Spring Boot, Maven, Gradle, or a legacy architecture, I will identify compatibility issues, modernize outdated dependencies, and ensure your application runs reliably on Java 21.
Ideal for businesses looking to improve performance, security, maintainability, and long-term support while reducing technical debt and modernization risks.
You will receive a clean, tested, and production-ready Java 21 upgrade with clear documentation of all changes performed during the migration process.
This service includes Java version migration, dependency compatibility review, build configuration updates, code refactoring where required, issue resolution, testing support, and deployment readiness validation.
Whether your application is built using plain Java, Spring Framework, Spring Boot, Maven, Gradle, or a legacy architecture, I will identify compatibility issues, modernize outdated dependencies, and ensure your application runs reliably on Java 21.
Ideal for businesses looking to improve performance, security, maintainability, and long-term support while reducing technical debt and modernization risks.
You will receive a clean, tested, and production-ready Java 21 upgrade with clear documentation of all changes performed during the migration process.
Programming Languages
JavaScript, JavaCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included $299
These options are included with the project scope.
$299
- Delivery Time 3 days
- Number of Revisions 1
- Source Code
Frequently asked questions
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PS
Philippe S.
Jan 30, 2025
Integration testing
Niravdas is very skilled and highly reliable. I shall work with him again when the next opportunity arises.
RA
Reza A.
Oct 26, 2024
Java Backend- and Webdeveloper with Spring and Javascript Expertise
ST
Sachin T.
Oct 26, 2024
Kotlin Web Development (Spring BFF)
Yes, performed well, and had other team members to support him (though I found that out later)
This area was relatively new to him, but he had already hand-on experience with Java, and Spring (Boot, Session, and Security).
Overall, I would recommend him, if you have a short, medium or long term project
This area was relatively new to him, but he had already hand-on experience with Java, and Spring (Boot, Session, and Security).
Overall, I would recommend him, if you have a short, medium or long term project
ST
Shekar T.
Jun 26, 2024
Need to upgrade an API using spring frame to create consumer groups on Kafka
Niravdas has a very good knowledge on the springframe work. He understood the requirements very quickly and was able to deliver on time. He also quickly reacts and take complete ownership of the issues. Would highly recommend him
AK
Ankur K.
Jun 19, 2024
Java Rest API
Niravdas is a professional and an expert and helped me with my work deliverables.
About Niravdas
AI-Powered Java Backend Developer | Spring Boot | AWS | SaaS
100%
Job Success
Ahmedabad, India - 6:17 am local time
⚡ 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?
Steps for completing your project
After purchasing the project, send requirements so Niravdas can start the project.
Delivery time starts when Niravdas receives requirements from you.
Niravdas works on your project following the steps below.
Revisions may occur after the delivery date.
Codebase Review & Upgrade Planning
Review the existing application, Java version, dependencies, build tools, and identify compatibility issues before preparing the upgrade strategy.
Java 21 Migration & Modernization
Upgrade the application to Java 21, update dependencies, resolve compatibility issues, and modernize build configurations where required.