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

%CF; Design and implement RESTful APIs following established architectural pattern

%CF; Develop and maintain backend features for project management, resource allocation,

time tracking, and expense management modules.

%CF; Participate in AI/ML feature development using LangChain4j and Spring AI

frameworks

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

%CF; Implement business logic for approval workflows and process automation

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

providers)

%CF; Develop scheduled background, data synchronization, and forecasting

%CF; Ensure proper security implementation through ACL and role based access control

Required Technical Skills

Technologies & Frameworks

%CF; Backend: Spring Boot 3.x, Spring MVC, Spring AOP, Spring WebSocket

%CF; ORM: Apache Torque with Criteria-based query building

%CF; Database: PostgreSQL with pgvector for AI embeddings

%CF; Security: OneLogin SAML, Google Authenticator, jBCrypt

%CF; Integrations: QuickBooks SDK, Zapier, Google services, MPXJ

Architecture & Design Patterns

%CF; Service Layer Pattern and Repository Pattern

%CF; Singleton, Factory, and Decorator patterns

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

%CF; Multi-layered architecture design

%CF; Understanding of domain-driven design principles

Database & Data Management

%CF; PostgreSQL or similar relational databases

%CF; Transaction management and data integrity

%CF; Query optimization and performance tuning

%CF; Database migration and schema management

%CF; Experience with Criteria based query builder

Experience Level

5+ years of professional Java backend development experience with:

%CF; At least 2 years working with Spring Framework

%CF; Experience with enterprise-level applications

%CF; Understanding of multi-tenant architectures (preferred)

%CF; Exposure to project management or ERP systems (nice to have)

Soft Skills & Work Approach

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

%CF; Code Quality: Writing maintainable, well structured code following established

patterns

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

%CF; Documentation: Creating clear technical documentation and code comments

%CF; Learning Agility: Quickly understanding new domains and technologies

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

workflows

Desired Technical Skills

%CF; Frontend Basics: Understanding of React and REST API consumption patterns

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

etc.)

%CF; Background Processing: Quartz scheduler or similar job scheduling frameworks

%CF; Reporting Engines: Experience with data visualization and reporting libraries

%CF; AI/ML Integration: LangChain4j, Spring AI, or similar AI frameworks

Why This Role is Interesting

%CF; Complex Domain: Work on sophisticated business logic

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

extensible systems

%CF; Modern Tech: Actively integrating AI/ML capabilities into production

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

patterns

%CF; Impact: Your work directly affects project management workflows for enterprise

clients\

%CF; Growth: Exposure to diverse technical challenges from scheduling algorithms to AI

integration