Challenge

Design and implement a RESTful API (including data model and the backing implementation) for money transfers between accounts.

Explicit requirements:

1. You can use Java or Kotlin.
2. Keep it simple and to the point (e.g. no need to implement any authentication).
3. Assume the API is invoked by multiple systems and services on behalf of end users.
4. You can use frameworks/libraries if you like (except Spring), but don't forget about requirement #2 and keep it simple and avoid heavy frameworks.
5. The datastore should run in-memory for the sake of this test.
6. The final result should be executable as a standalone program (should not require a pre-installed container/server).
7. Demonstrate with tests that the API works as expected.

Implicit requirements:

1. The code produced by you is expected to be of high quality.
2. There are no detailed requirements, use common sense.

How to

Build package

./mvnw clean package

Run app

java -jar target/no-spring-transfer-1.0.0-SNAPSHOT-runner.jar

Run tests

./mvnw clean test

Stack

1. Java 11
2. Quarkus framework: https://quarkus.io/
3. H2 database (in-memory)
4. Project Lombok
5. Flyway migration engine

API entry-points

• GET http://localhost:8080/account?page=0&limit=5 - - get information about all accounts in system
• GET http://localhost:8080/account/{id} - get information about specific account
• POST http://localhost:8080/transaction - create new transaction
• GET http://localhost:8080/transaction?page=0&limit=200 - get list of transactions