# Architecture and Technologies

## Technologies Used

### PostgreSQL

PostgreSQL was selected as the primary database for its reliability, ACID compliance, and advanced features like JSONB support, which are useful for handling semi-structured data.

### Redis

Redis is used for caching and session management due to its in-memory data store capabilities, which provide extremely low-latency data access.

### MinIO

MinIO serves as the object storage solution, offering S3-compatible APIs. It is lightweight, performant, and ideal for storing large amounts of unstructured data.

### Docker and Docker Compose

Docker is used to containerize the application, ensuring consistency across development and production environments. Docker Compose simplifies the orchestration of multiple services during development.

### Nginx

Nginx is used as a reverse proxy and load balancer to distribute traffic efficiently and ensure high availability.

### Makefile

The Makefile is used to automate common tasks such as building, testing, and running the application, improving developer productivity.

## Services Architecture

### Auth Service

- **Responsibilities**: Handles user authentication and authorization.
- **Endpoints**: Defined in `auth.proto`.

### User Service

- **Responsibilities**: Manages user profiles and related data.
- **Endpoints**: Defined in `user.proto`.

### Competition Service

- **Responsibilities**: Manages competitions, including creation, updates, and participant management.
- **Endpoints**: Defined in `competition.proto`.

### Task Service

- **Responsibilities**: Handles tasks within competitions, including creation and updates.
- **Endpoints**: Defined in `task.proto`.

### Submission Service

- **Responsibilities**: Handles submissions made by users for tasks.
- **Endpoints**: Defined in `submission.proto`.
- **Additional Logic**: Sends messages to Kafka for downstream processing.

### Checker Adapter Service

- **Responsibilities**: Processes new submissions by running checks and validations.
- **Additional Logic**:
  - Reads new submission messages from Kafka.
  - Runs Kubernetes pods to execute the checker logic.
  - Retrieves results and updates the database.

#### Results Service

- **Responsibilities**: Manages and retrieves results for tasks and competitions.
- **Endpoints**: Defined in `results.proto`.

#### Review Service

- **Responsibilities**: Handles reviews for submissions.
- **Endpoints**: Defined in `review.proto`.

#### Achievements Service

- **Responsibilities**: Manages user achievements and badges.
- **Endpoints**: Defined in `achievements.proto`.

### Communication and Workflow

- **Kafka**: Acts as the message broker for asynchronous communication between the `Submission Service` and the `Checker Adapter Service`.
- **Kubernetes**: Used by the `Checker Adapter Service` to dynamically run pods for executing submission checks.
- **PostgreSQL**: Centralized database for storing results and other persistent data.