Flutter is an excellent framework for building high-quality mobile applications. However, developing high-performance Flutter apps requires a good understanding of best practices and techniques that can optimise the app's performance. Here are ten best practices that can help you build high-performance Flutter apps:

1. Use widgets efficiently: Widgets are the building blocks of Flutter apps. It's essential to use widgets efficiently to avoid creating unnecessary widgets that can slow down the rendering engine. Use stateless widgets when possible to reduce the load on the rendering engine. By employing the expertise of a professional Flutter development services provider, you can ensure that your app is built using the best practices and techniques, resulting in an optimised and responsive app that meets your business needs.
   
   
2. Optimise images: Images can be memory-intensive, and using too many images or large images can increase the app's memory usage. Optimise images by using compressed images and minimising their size to reduce the memory used by the app.
   
   
3. Use asynchronous operations: Use asynchronous operations whenever possible to ensure that the app remains responsive, even when performing long-running tasks. For example, when loading data from a server or a database, use asynchronous APIs to prevent the app from freezing.
   
   
4. Use background processing: Use background processing to perform tasks that are not time-critical, such as downloading or processing data. By moving these tasks to the background, you can free up the main thread and prevent the app from becoming unresponsive.
   
   
5. Avoid unnecessary rebuilding: Avoid unnecessary rebuilding of widgets by using keys to identify widgets that need to be updated. By using keys, you can prevent the app from rebuilding the entire widget tree, improving performance.
   
   
6. Optimise animations: Animations can be CPU-intensive and can affect the app's performance. Use the Flutter animation system and avoid using complex animations to reduce the load on the CPU.
   
   
7. Use code splitting: Code splitting is a technique that can improve app performance by reducing the size of the app's code. By splitting the app's code into smaller chunks and loading only the necessary code when needed, you can reduce the app's startup time and memory usage.
   
   
8. Minimise the use of plugins: Plugins can provide additional functionality to the app, but they can also slow down the app's performance. Minimise the use of plugins and only use plugins that are necessary for the app's functionality.
   
   
9. Optimise the layout: Optimise the layout of the app's widgets to reduce the number of layers and the complexity of the widget tree. By simplifying the widget tree, you can improve the app's performance and reduce memory usage.
   
   
10. Use profiling tools: Use profiling tools to identify performance bottlenecks in the app. Profiling tools can help you identify memory leaks, slow rendering, or CPU-intensive tasks, allowing you to optimise the app's performance.

In conclusion, building high-performance Flutter apps with the help of a reliable Flutter app development company requires a good understanding of best practices and techniques that can optimise the app's performance. By using widgets efficiently, optimising images, using asynchronous operations, and background processing, avoiding unnecessary rebuilding, optimising animations, using code splitting, minimising the use of plugins, optimising the layout, and using profiling tools for Flutter app development, the Flutter app development company can build high-performance Flutter apps that provide a smooth and responsive user experience.