J2EE Jobs

deploying the official open-source backend components and integrating them with various third-party services for full functionality. • mainly our requirements our own infrastructure Self-Hosted with Custom Instance public rebranded messaging app. • Only people who have previously studied and worked on production-style Signal server architecture and structure should communicate • Those who have not previously studied and worked on production-style Signal server architecture and structure should not submit bid proposals. • The official source code is open-source and available on GitHub. • You only need to deploy and configure the Signal server only. The process requires significant technical expertise in server management, Java, database administrat...

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...

Busco desarrollar el backend de un sistema empresarial centrado en el seguimiento de procesos, específicamente el seguimiento de tareas diarias. Qué necesito: • Arquitectura robusta con API REST bien documentada. • Modelo de datos que permita crear, asignar, actualizar y cerrar tareas; registrar tiempos y responsables; generar estados de avance. • Autenticación y control de roles (admin, supervisor, operario). • Endpoints optimizados para reportes en tiempo real y paneles de KPI. • Entorno listo para escalar (idealmente Node.js + Express o Java Spring; estoy abierto a otros stacks si justificas ventajas). • Pruebas unitarias y de integración básicas, así como guía breve de despliegue en cloud (AWS, A...