When developing applications with Angular, adhering to best practices is essential for ensuring maintainability, scalability, and performance. Here are the Top 10 Angular Best Practices every developer should know:

1. Modular Architecture: Structure your application into modules to promote reusability and separation of concerns.
2. Use Lazy Loading: Implement lazy loading for feature modules to improve the performance by reducing the initial load time.
3. Follow Angular Style Guide: Familiarize yourself with the official Angular Style Guide to enforce consistency and best coding standards.

Additionally, consider the following best practices to enhance your Angular applications further:

4. Utilize Reactive Programming: Leverage RxJS for handling asynchronous operations to make your application more efficient.
5. Optimize Change Detection: Use OnPush change detection strategy wherever applicable to minimize unnecessary checks.
6. Write Unit Tests: Ensure you write comprehensive unit tests to verify your components and services, which helps maintain a high-quality codebase.
7. Engage in Performance Profiling: Regularly use tools like the Angular DevTools to evaluate your application’s performance and identify bottlenecks.
8. Keep Dependencies Updated: Regularly update your Angular dependencies to stay aligned with the latest security patches and performance improvements.
9. Utilize Environment Variables: Use environment variables to manage configurations for different environments (development, testing, production).

Angular is a powerful framework for building dynamic web applications; however, developers often fall into common pitfalls that can hinder performance and maintainability. One of the frequent mistakes is neglecting proper architecture. It's crucial to organize your application in a scalable way by using modules effectively. Developer teams should implement a feature-rich architecture whereby components are decoupled and reusable. This approach simplifies maintenance and enhances collaboration among team members.

Another prevalent issue is inefficient change detection. Angular's change detection strategy can be resource-intensive if not appropriately handled. Developers often overlook the importance of using the OnPush strategy to limit performance overhead. This strategy helps in minimizing the number of checks Angular needs to perform. Furthermore, leveraging observables and unsubscribing from them when no longer needed can drastically improve application responsiveness, leading to a better user experience.

Building a scalable Angular application requires a solid foundation and a thoughtful approach to architecture. Start by adhering to the Modular Development principle, where your application is divided into reusable components. This will not only enhance maintainability but also promote collaboration among team members. Additionally, be sure to utilize Angular's Lazy Loading feature to load modules on-demand, thus improving performance and loading times. Implementing state management solutions, such as NgRx, can also aid in managing the application state effectively, preventing issues as your application grows.

Another essential strategy for creating a scalable Angular application is to establish clear coding standards and conventions. This includes using a standardized folder structure, naming conventions, and comment practices. Consistency in your codebase will help new developers ramp up quickly and greatly reduce the likelihood of errors. Finally, make use of Angular's Reactive Forms and services for handling forms and business logic, which allows for greater flexibility and reusability. By following these tips and strategies, you can ensure that your Angular application remains robust and scalable as it evolves.