Celoxis- Medior Backend Java Developer

Medior Backend Java Developer

About the Project

Join our team and work on a mature, feature-rich Project & Service Automation (PSA)

platform, an enterprise-grade solution that powers project management, resource planning,

time tracking, expense management, and business reporting for global customers. Our

platform supports multi-tenant environments with complex business workflows, and we are

actively expanding its capabilities with advanced AI/ML features.

Key Responsibilities

Design and implement RESTful APIs following established architectural pattern

Develop and maintain backend features for project management, resource allocation,

time tracking, and expense management modules.

Participate in AI/ML feature development using LangChain4j and Spring AI

frameworks

Work with ORM to build complex database queries and optimize data access layers

Implement business logic for approval workflows and process automation

Integrate third-party services (accounting systems, CRM platforms, authentication

providers)

Develop scheduled background, data synchronization, and forecasting

Ensure proper security implementation through ACL and role based access control

Required Technical Skills

Technologies & Frameworks

Backend: Spring Boot 3.x, Spring MVC, Spring AOP, Spring WebSocket

ORM: Apache Torque with Criteria-based query building

Database: PostgreSQL with pgvector for AI embeddings

Security: OneLogin SAML, Google Authenticator, jBCrypt

Integrations: QuickBooks SDK, Zapier, Google services, MPXJ

Architecture & Design Patterns

Service Layer Pattern and Repository Pattern

Singleton, Factory, and Decorator patterns

Event-driven architecture (pub/sub, event listeners)

Multi-layered architecture design

Understanding of domain-driven design principles

Database & Data Management

PostgreSQL or similar relational databases

Transaction management and data integrity

Query optimization and performance tuning

Database migration and schema management

Experience with Criteria based query builder

Experience Level

5+ years of professional Java backend development experience with:

At least 2 years working with Spring Framework

Experience with enterprise-level applications

Understanding of multi-tenant architectures (preferred)

Exposure to project management or ERP systems (nice to have)

Soft Skills & Work Approach

Problem Solving: Ability to navigate and understand large, complex codebases

Code Quality: Writing maintainable, well structured code following established

patterns

Collaboration: Working with cross-functional teams (frontend, QA, product)

Documentation: Creating clear technical documentation and code comments

Learning Agility: Quickly understanding new domains and technologies

Attention to Detail: Ensuring data integrity and business rule compliance in complex

workflows

Desired Technical Skills

Frontend Basics: Understanding of React and REST API consumption patterns

Integration Experience: Webhooks, third-party API integration (QuickBooks, Zapier,

etc.)

Background Processing: Quartz scheduler or similar job scheduling frameworks

Reporting Engines: Experience with data visualization and reporting libraries

AI/ML Integration: LangChain4j, Spring AI, or similar AI frameworks

Why This Role is Interesting

Complex Domain: Work on sophisticated business logic

Architecture: Learn advanced patterns in multi-tenancy, event-driven design, and

extensible systems

Modern Tech: Actively integrating AI/ML capabilities into production

Scale: Navigate and contribute to a large, mature codebase with established

patterns

Impact: Your work directly affects project management workflows for enterprise

clients\

Growth: Exposure to diverse technical challenges from scheduling algorithms to AI

integration