Java Spring Boot Backend Build -- 2

I am setting up a new service and require an experienced Java Backend Developer to design and develop the server-side application from scratch. The technology stack will be based on Java and Spring Boot, following a clean and modular architecture that can later evolve into independent microservices.

Core Responsibilities
Develop well-structured REST APIs supporting CRUD operations and domain-specific workflows.
Design and manage MySQL database schemas using Spring Data JPA, including optimized tables, indexing, and migrations for performance and data integrity.
Implement secure API access using Basic Authentication, while maintaining flexibility for future migration to OAuth2 or JWT-based authentication.

Implement robust validation, centralized exception handling, and detailed logging for efficient debugging and monitoring.
Integrate third-party services such as payment gateways (Stripe or PayPal) and messaging platforms (Twilio or AWS SNS/SQS) for notifications.

Develop unit and integration tests along with basic performance benchmarking to validate scalability.
Containerize the application using Docker (with docker-compose support) and provide clear documentation for setup and execution.

Acceptance Criteria
The project will be considered complete when:
Application containers start successfully and the health-check endpoint responds correctly.
All APIs function properly via Postman with correct authentication, validation, and database persistence.
Sandbox payment and notification workflows execute successfully with expected callbacks.
Provided tests and performance benchmarks run successfully with documented results.

Required Skills
Java 17+
Spring Boot & Spring Security
JPA / Hibernate
REST API Development
MySQL
Maven or Gradle
Microservices Architecture
Docker & CI/CD practices

Strong coding standards, scalability awareness, and performance optimization experience are highly preferred.