Property Tax Architecture

Overview

The DIGIT Property Tax module implements a microservices architecture with clearly defined core services, common services, and reusable components. The system follows event-driven patterns using Kafka for asynchronous processing and maintains data consistency through well-defined service interactions.

The Property Tax module consists of three main microservices:

  1. property services - Legacy property management services

  2. pt-services-v2 - Modern property management services

  3. pt-calculator-v2 - Billing and tax calculation service

property-tax/
├── property-services/       # Legacy property management service
├── pt-services-v2/         # Modern property management service (V2)
└── pt-calculator-v2/       # Billing and tax calculation service (V2)

1. property-services - Legacy Property Management Service

The original property management service that handles comprehensive property data management, including:

  • Property master data management

  • Owner and institutional ownership tracking

  • Property addresses with geolocation support

  • Unit/floor-level details

  • Property assessments for each financial year

  • Document management (property documents, owner documents, assessment documents)

  • Draft property submissions

  • Property migration tracking

  • Data encryption audit trails

Key Features:

  • Complete CRUD operations for properties and assessments

  • Support for both individual and institutional ownership

  • Multi-unit/floor property support

  • Comprehensive address management with GPS coordinates

  • Financial year-based assessments

  • Full audit trail through dedicated audit tables

  • Property migration support from legacy systems

  • Data encryption capabilities

2. pt-services-v2 - Property Management Service V2

Modern redesigned service for property tax management with improved data structure:

  • Streamlined property registration and management

  • Enhanced owner information management

  • Improved address and geolocation tracking

  • Property detail and assessment management

  • Unit-level property management

  • Document management for properties and owners

  • Institutional ownership support

  • Draft property submissions

  • Comprehensive audit trails

Key Features:

  • Simplified and efficient data model

  • JSONB support for flexible additional data

  • Enhanced indexing for better performance

  • Support for ad-hoc exemptions and penalties

  • Improved multi-tenancy support

  • Financial year-based property details

  • Annual Rental Value (ARV) tracking

  • Construction type and usage category management

3. pt-calculator-v2 - Tax Calculation Service V2

Specialised service handling all property tax calculations and billing:

  • Billing slab configuration based on multiple property parameters

  • Property tax calculation using configurable rate structures

  • Mutation fee calculation for ownership transfers

  • Assessment record management

  • Dynamic rate determination based on:

    • Property type and subtype

    • Usage categories (Major/Minor/Sub-minor/Detail)

    • Ownership categories

    • Floor levels

    • Plot size ranges

    • Occupancy type

    • Area type

    • Market value (for mutation fees)

Key Features:

  • Flexible multi-parameter billing slab system

  • Support for unit rate and ARV percentage-based calculations

  • Unbuilt land tax calculation

  • Mutation fee calculation with fixed and percentage methods

  • Market value-based fee determination

  • Assessment of demand linking

  • Tenant-specific rate configuration

  • Multi-floored property support

Technology Stack

  • Framework: Spring Boot (Java 8+)

  • Database: PostgreSQL 9.6+

  • Migration Tool: Flyway

  • Data Formats: JSON/JSONB for flexible data storage

  • Architecture: Microservices-based

  • Multi-tenancy: Supported across all services

Module Package Structure

The Property Tax module follows DIGIT’s layered, event-driven architecture with a clear separation of responsibilities across packages. This makes the codebase easier to understand, navigate, and maintain.

Configuration is kept in config, business logic in service, utilities and constants in util, and validations in validator. Data access and external integrations are handled by the repository, with a builder for queries and a rowmapper for mapping database results. The web layer exposes APIs through controllers and defines request/response objects in models, while Kafka-based messaging is managed through consumer and producer packages.

The Property Tax Calculator module follows DIGIT’s event-driven microservices architecture. Its package structure separates messaging, data access, business logic, and configuration, making the codebase easier to understand and maintain.

Kafka interactions are handled through dedicated consumers and producers, database access is managed by repository and query-builder packages, domain data is defined in models, and all service and infrastructure settings are grouped under config.

Core Components

The core components encapsulate the key business workflows of the module. Listed below are the key components used by the module.

  • Calculator Service: Implements property tax calculation rules

  • Demand Service: Manages demand creation and updates

  • Billing Integration: Interfaces with the billing service

  • Finance Integration: Posts transactions to the finance system

  • Notification Service: SMS and email notifications to citizens and officials at relevant stages

PreviousProperty Tax SystemNextProperty Tax Database Schemas

Last updated

Was this helpful?