Local Development

See: docs/local-development.md

Testing

See: docs/testing.md

Student Card Platform - AWS Lambda (Local SQS + DLQ + Idempotency)

This is a single Spring Boot Maven project that demonstrates a real-world flow:

• REST API receives a student credit card application
• Application is persisted in H2
• An async event is published to SQS (LocalStack)
• A worker poller processes SQS messages like a Lambda consumer
• Idempotency is enforced via Redis (SETNX + TTL)
• Retries happen automatically if processing fails
• Poison messages are routed to DLQ after maxReceiveCount

Tech

• Java 17
• Spring Boot 3
• Maven
• LocalStack (SQS + DLQ)
• Redis (idempotency)
• H2 (local persistence)
• Testcontainers (integration tests)

---

1) Prerequisites

• Java 17 installed
• Maven installed (or use IntelliJ Maven integration)
• Docker installed and running

---

2) Create project in IntelliJ

1. File -> New -> Project

2. Choose Maven

3. GroupId: com.northstar

4. ArtifactId: student-card-platform

5. Name: student-card-platform

6. JDK: 17

7. Finish

8. REST endpoint (API)

9. “Lambda-like” async worker (SQS consumer) running inside the same Spring Boot app

10. Idempotency/dedup using Redis (local via Docker)

11. Retries + DLQ using SQS redrive policy (local via LocalStack)

12. Integration tests using Testcontainers (runs fully on your machine)

Then replace/add files exactly as in this repository.

---

3) Start local infrastructure (LocalStack + Redis)

From project root:

docker compose up -d