Yoda Response: Ensured scalability and maintainability, I have, by following best practices and principles. Designed systems with modular architecture, I did, allowing individual components to be scaled independently. For example, in a text-to-speech project, created a base engine class that could handle multiple engines, I did. If one engine failed, another could take over seamlessly. Used design patterns like Singleton and Factory to ensure flexibility and extensibility, I have. For maintainability, wrote clean, well-documented code and implemented comprehensive unit tests. Also, employed CI/CD pipelines to automate testing and deployment, ensuring that changes could be integrated smoothly without disrupting the system. Regular code reviews and refactoring, we did, to keep the codebase healthy and maintainable in the long run.