J2EE Jobs

I am a Software Developer with over 7 years of hands-on experience in Java and AWS services, and I am excited to begin my freelancing journey on Upwork. Throughout my professional career, I have designed, developed, and maintained scalable, secure, and high-performance applications while ensuring reliability and cost-efficient cloud operations. My expertise includes core Java development, Spring-based applications, REST APIs, AWS services such as Lambda, ECS, DynamoDB, S3, CloudWatch, and Infrastructure as Code using Terraform. I focus on writing clean, maintainable code, delivering production-ready solutions, and resolving issues quickly to keep systems stable and secure. As I start my freelancing career, I am fully committed to delivering high-quality work, meeting deadlines consistent...

I need a versatile full-stack Java developer who can dedicate a full 8-hour shift aligned with Pacific Standard Time. The work revolves around a new enterprise platform we are rolling out internally, and I expect you to be comfortable owning both back-end Java code and the corresponding front-end layer. Scope of the build The application’s first release must cover three core capabilities: • User management • Data analytics • Workflow automation We will tackle these features in two-week Agile sprints, with planning, daily stand-ups, and sprint reviews held on my calendar in PST. You will demo working software at the end of every sprint so we can decide together what to refine next. Your day-to-day – Write clean, tested Java code and wire it to a modern fr...

I'm looking for an experienced Java developer to build a web application using the Spring framework. The app needs to support user authentication, data management, and reporting and analytics functionalities. Key Requirements: - Robust user authentication system - Comprehensive data management capabilities - Advanced reporting and analytics features Ideal skills and experience: - Strong proficiency in Java and Spring framework - Experience in developing secure authentication mechanisms - Expertise in data management and analytics tools - Familiarity with web application architecture and design principles - Ability to write clean, maintainable code and work collaboratively Please provide your portfolio and relevant project experience.

My Java-based desktop application currently throws errors whenever a user tries to import an Excel file, and the files it exports need a small formatting tweak before they are usable. The rest of the program works well, so I’m looking for someone who can go straight to the file-handling layer, diagnose the functional bugs, and leave the UI and business logic untouched. Here’s what I need from you: • Identify and resolve the exception that appears during Excel import (the stack trace will be provided). • Adjust the export file so that matches the format required (change date in american format to eu format). • Keep the fixes confined to the existing codebase—no major rewrites—while following the project’s current build process (Maven, Java...

I’m building a new mobile application and I need a robust Java Spring Boot backend to power it. The core services you’ll create must cover: • User authentication and management with full multi-factor authentication (MFA) and support for future multi-party authentication flows. • A streamlined customer-onboarding journey that begins with registration and ends with a verified, fully profiled user record. • Reliable data storage and retrieval using a relational engine—MySQL or PostgreSQL, whichever you are most comfortable optimising. RESTful APIs should be documented with Swagger/OpenAPI, secured with JWT or a similarly strong token strategy, and thoroughly unit- and integration-tested. I’ll provide the mobile team’s contract-first API s...