Prism is an industrial-grade, high-throughput distributed search and discovery engine built on the CQRS (Command Query Responsibility Segregation) pattern. It leverages modern Java 21 capabilities to provide real-time data synchronization between a relational source of truth and a full-text search Read-Model.

The project implements a resilient event-driven pipeline:

1. Command Side (Write-Model): A Spring Boot service managing event ingestion into PostgreSQL.
2. CDC Bridge: Debezium monitors Postgres WAL (Write-Ahead Logs) and streams changes to Kafka.
3. Query Side (Read-Model): A high-concurrency service consuming Kafka signals to project data into Elasticsearch.

• Java 21 Virtual Threads (Project Loom): Optimized for high-throughput I/O between Kafka and Elasticsearch without thread starvation.
• Change Data Capture (CDC): Real-time synchronization using Debezium, ensuring the Read-Model is eventually consistent with the Source of Truth.
• Advanced Discovery:
  • Fuzzy Search: Typo-tolerant querying using Elasticsearch Native Query DSL.
  • Hit Highlighting: Automatic HTML match indication (<em> tags) in search results for enhanced UX.
• Production Resilience:
  • Non-blocking Retries: Exponential backoff strategy for transient failures.
  • Dead Letter Topics (DLT): Fault-tolerant event handling to prevent data loss.
• Industrial Standards: Multi-module Maven architecture, strictly typed DTOs using Java Records, and conventional git-flow.

• Runtime: Java 21 (Virtual Threads enabled)
• Framework: Spring Boot 3.4.2
• Database: PostgreSQL 16 (Logical Replication)
• Messaging: Apache Kafka
• Search Engine: Elasticsearch 8.11
• Ingestion: Debezium Connect
• Build Tool: Maven (Multi-Module)

prism/
├── prism-command-service/   # Write Model (API → PostgreSQL)
├── prism-search-service/    # Read Model (Kafka → Elasticsearch → Search API)
├── docker-compose.yml       # Infrastructure orchestration
└── pom.xml                  # Parent POM & dependency management

## 🚦 Getting Started

### Prerequisites
- Java 21 SDK
- Maven 3.9+
- Docker & Docker Compose

Spin up the distributed backbone:

docker-compose up -d

Build & Run From the root directory:

mvn clean install -DskipTests

cd prism-command-service && ./mvnw spring-boot:run

cd prism-search-service && ./mvnw spring-boot:run

Endpoint

POST http://localhost:8080/api/v1/events

Payload

{
  "title": "Smile Khan Flagship Project",
  "category": "ENGINEERING",
  "metadata": {
    "status": "active"
  }
}

Endpoint: POST http://localhost:8081/api/v1/discovery/search

Payload

{
  "query": "Flagship",
  "category": "ENGINEERING",
  "page": 0,
  "size": 10
}

Smile Khan
Java Backend Engineer | Distributed Systems & Event-Driven Architectures