Stability and Security

The Kivy project was built with security and reliability as foundational principles, ensuring user trust and data protection across all platforms: iOS, web, and desktop.

Application Security

• The iOS app, developed in SwiftUI, is tightly integrated with the Apple ecosystem, benefiting from its advanced security features:
• Sandbox isolation prevents unauthorized access to app data.
• Biometric authentication (Face ID / Touch ID) ensures secure user verification.
• Keychain integration enables encrypted storage of sensitive user credentials.

• All communication between the frontend and backend occurs over encrypted HTTPS connections.
• The backend API, built with NestJS, is protected by:
• JWT-based authentication with short-lived tokens.
• Rate limiting to mitigate abuse and denial-of-service attempts.
• CORS restrictions and access control mechanisms to prevent unauthorized access.

• The backend is hosted on a secure, access-restricted server that is actively monitored. Critical data is stored in a hardened database, following current security best practices:
• User passwords are hashed using bcrypt with 10 rounds of salting, making brute-force attacks computationally impractical.
• Protection against common web threats such as:
• SQL Injection
• Cross-Site Scripting (XSS)
• Cross-Site Request Forgery (CSRF)

• Both the frontend and backend handle errors and exceptions in a standardized manner, returning appropriate status codes and messages while avoiding information leaks.

Testing and Stability

To ensure a stable and high-quality product, we adopted a comprehensive testing strategy covering both functional and non-functional aspects:

• End-to-end (E2E) testing was implemented on the backend to automatically verify critical flows and inter-component communication.
• Manual testing was performed on all major platforms (iOS, web, desktop, and backend) to validate real-world behavior and user interactions.
• API endpoints were rigorously tested using Postman collections to ensure robustness and consistency across various usage scenarios.

Non-functional Testing Highlights:

• Performance and scalability testing in isolated environments helped simulate high-traffic scenarios and critical service failures (e.g., network outages, database disconnections).
• Cross-platform compatibility was validated across multiple hardware configurations to ensure seamless operation in both high-end and resource-constrained environments.

Automation and Quality Assurance:

• A large portion of the testing process is automated through test scripts, enabling rapid validation of application stability after each code change.
• All bugs, test results, and QA feedback were tracked and managed within Trello, ensuring issues were documented, prioritized, and resolved efficiently.
• The structured QA pipeline ensured the development process remained predictable, repeatable, and quality-focused.

By integrating modern security practices with thorough testing and quality assurance workflows, we have built a resilient and secure application architecture — one that is ready for production use and scalable future development.