Development of a GDPR-Compliant Chat Module for SynComNet

SynComNet GmbH, based in Münster, develops modern software solutions for workforce and shift planning. With products like PERS|PLAN|NET, the company helps security services, facility management firms, and other service providers efficiently plan, communicate, and coordinate personnel and operations. To offer customers a secure and fully integrated communication option, SynComNet commissioned the development of a chat module seamlessly embedded into their system environment.

Goal: Simplify day-to-day communication between dispatchers, site managers, and employees—without relying on external tools like WhatsApp—while ensuring full GDPR compliance.

SynComNet wanted to give its customers the ability to manage team communication directly within the planning software—secure, transparent, and fully integrated.

Key requirements for the new solution included:

• Centralized, GDPR-compliant communication without third-party messaging apps.
• Direct linkage of chats to sites, shifts, and events within PERS|PLAN|NET.
• Automatic creation of chat groups when new events or locations are added.
• Easy usability for dispatchers via web and for employees via the mobile app.
• High system stability and fast response times enabled by modern cloud architecture.

The jointly developed chat module was built as a standalone cloud service, providing an API for seamless integration with the PersPlan system.

Technical Architecture and Features

• Backend: Node.js with NestJS and Express
• Frontend: Vue.js + Tailwind CSS
• Database: Azure Cosmos DB
• Caching: Redis Cache
• Real-Time Communication: WebSocket
• Deployment: Docker, Azure Cloud, GitLab CI/CD

The software follows a modular monolith architecture, combining scalability, performance, and maintainability in an optimized way.

Modular Functional Structure

The system is structured into six functional modules:

1. Authentication: User login via dropdown menu (currently in testing phase)
2. Chat List Module: Overview of active chats, sorted by activity, with visual unread indicators and pinning function
3. Chat View Module: Chronological display with read receipts, sender details, and clear layout
4. Message Sending Module: Input, validation, and client-side error-handling for sending text messages
5. Message Receiving Module: Real-time delivery with auto-sync after connection recovery
6. Chat Management Module: Creating, editing, and deleting chats, managing participants, soft delete functionality

User Interface

• Simple and intuitive navigation
• Notification indicators for unread messages
• Responsive design for both browser and mobile app use

Integration

Communication between PERS|PLAN|NET and the chat module occurs via a flexible API interface. The chat system can be fully controlled using straightforward API calls from PERS|PLAN|NET.

Access permissions are handled by an internal authorization system, allowing for user-specific configurations. This dynamic permission logic ensures that role-based access control remains within PERS|PLAN|NET, keeping the chat system clean and manageable.

• Seamless integration: The chat module operates independently of PERS|PLAN|NET, allowing for its further development without dependency on the core system. New features can be added and accessed via simple API calls. Additionally, a crash in the chat system does not impact PERS|PLAN|NET thanks to the separated infrastructure.
• Response time under 3 seconds: Real-time communication with high reliability.
• Data protection compliance: All data is stored within the Azure cloud environment—fully GDPR-compliant.
• High user adoption: Dispatchers and staff actively use the integrated solution instead of third-party messengers.
• Future-ready: The modular architecture supports future expansions such as file sharing or video chat.