Midas Core: Financial Transaction & Incentive Engine

Midas Core is a distributed financial processing system built with Spring Boot and Apache Kafka. It handles high-volume transaction processing, real-time balance management, and integrates with external microservices to apply transaction incentives.

🚀 System Architecture

The project follows a microservices-oriented architecture:

• Producer: Simulates financial transactions being sent to a Kafka topic.
• Midas Core (Consumer): Listens to Kafka, processes transactions, and updates the PostgreSQL/H2 database via Hibernate.
• Incentive API (External Service): A separate REST service that determines if a transaction qualifies for a reward/bonus.
• REST API: A balance inquiry endpoint that allows external systems to query user accounts in real-time.

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🛠️ Tech Stack

• Java 17
• Spring Boot 3.x (Web, Data JPA, Validation)
• Apache Kafka (Message Broker)
• Hibernate (ORM)
• JUnit 5 & Embedded Kafka (Testing)
• Lombok (Boilerplate reduction)

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📋 Features implemented

Task 1-2: Core Infrastructure

• Configured Kafka listeners to ingest Transaction objects.
• Implemented JPA entities for User and Transaction records.
• Established a relational database schema to track historical balances.

Task 3-4: The Incentive Logic

• Integrated an external Incentive API using RestTemplate.
• Developed logic to adjust transaction amounts based on external "bonuses" before updating account balances.

Task 5: RESTful Inquiry

• Created a GET /balance endpoint to retrieve real-time user data.
• Implemented a custom Balance foundation object for standardized API responses.
• Verified the full end-to-end flow (Kafka -> Processing -> Incentive -> REST) using a dedicated verifier test suite.

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⚙️ How to Run

1. Start the Incentive API:

   java -jar incentives-api.jar