Architecture

System Overview

• Runtime Stack: Django REST Framework application served from Docker containers, backed by PostgreSQL, with analytics powered by a custom modelling module.
• Hosting Pattern: Container stack deployed on AWS EC2, fronted by Nginx for TLS termination, caching, and static asset delivery.
• Automation: Cron-driven background jobs create surveys, execute modelling pipelines, and issue alerts without blocking API requests.
• Observability: Application logs streamed via Docker, PostgreSQL introspection through pgAdmin, and health endpoints ready for integration into CloudWatch or Datadog.

Infrastructure Topology

Full Stack Request Flow

Nginx Responsibilities

• Terminate HTTPS and enforce secure headers (HSTS, CSP).
• Reverse proxy API traffic to web container on port 8000.
• Serve cached static files from /var/www/luna/static/ for low latency.
• Expose /admin and /api under the same domain for simplicity; consider subdomains when scaling.

Application Layer

Layer	Responsibilities	Key Components
API Gateway	REST routing, serializers, authentication, permission enforcement	API endpoints, DRF views
Domain Layer	User management, course modules, surveys, and forms	Core business logic, data models
Modelling Layer	Kalman filter computations, analytics persistence, exports	Statistical analysis engine
Cron & Scheduling	Periodic job orchestration for surveys and analytics	Background job scheduler

Request Lifecycle Flow

Data Model Overview

Entity Relationship Diagram

Core Entities

University

• Represents educational institutions
• Contains multiple faculties and departments
• Supports multi-tenant platform architecture

User

• Email-based authentication system
• Three roles: Student, Lecturer, Administrator
• Linked to university affiliation

Student

• Extended user profile for student participants
• Stores demographic and academic background
• Tracks language preferences and financial support

Module (Course)

• Represents academic courses/subjects
• Configurable semester periods (Winter/Summer)
• Password-protected enrollment system
• Scheduled survey deployment days
• Active/Inactive status management

Enrollment

• Links students to their enrolled courses
• Prevents duplicate enrollments
• Tracks enrollment timeline

Survey

• Time-series survey instances for longitudinal data collection
• Auto-incremented sequence numbers per student
• Flexible JSON structure for diverse question types
• Completion tracking (Completed/Not Completed)
• Lifecycle status (Active/Archived)

Form Template

• Reusable questionnaire blueprints
• JSON-based flexible structure
• Created by lecturers and administrators

Form Response

• Student submissions to forms
• Tracks completion status and timestamps
• JSON storage for answers

Faculty

• Organizational units within universities
• Groups related departments and programs

Technology Stack

Backend Framework

• Django 4.2.5 - Model-View-Template architecture
• Django REST Framework 3.14.0 - RESTful API design
• Custom authentication - Email-based user system

Database

• PostgreSQL - ACID-compliant relational storage
• JSON fields - Flexible survey and form content
• Database adapter - psycopg2-binary

API & Documentation

• OpenAPI/Swagger - Interactive API documentation (drf-yasg)
• CORS support - Cross-origin resource sharing (django-cors-headers)

Task Scheduling

• django-cron - Periodic job execution
• Survey automation - Scheduled deployment system

Configuration & Deployment

• Environment management - python-decouple, python-dotenv
• Containerization - Docker, Docker Compose
• Web server - Nginx (reverse proxy, SSL termination)

Cloud Infrastructure

• Compute - AWS EC2 instances
• Deployment - Dockerized application on EC2
• Networking - Nginx reverse proxy with SSL/TLS

Deployment Architecture

Background Processing

1. Survey Generation - Runs twice daily; creates upcoming survey records based on module schedule and student enrollment.
2. Analytics Pipeline - Ingests completed surveys, executes Kalman smoothing, writes metrics to analytics tables for dashboards.

Security Architecture

Authentication & Authorization

• Email-based authentication (no username required)
• Secure password hashing using Django’s PBKDF2 algorithm
• Role-based access control (Student, Lecturer, Administrator)
• Session-based authentication framework

Data Protection

• Environment-based configuration (no hardcoded secrets)
• CORS policy enforcement for API security
• SQL injection prevention via ORM parameterization
• XSS protection through template auto-escaping

Infrastructure Security

• Container isolation and separation
• Docker bridge network segmentation
• HTTPS/TLS encryption in production (Nginx)
• Database access restricted to internal network

Related Documentation

• Overview - Platform introduction and research context
• Installation Guide - Environment setup instructions
• Student Experience - Student user workflows
• Lecturer Experience - Lecturer and researcher workflows