Here are a few techniques for optimizing JavaScript performance and reducing load times:

Code Splitting:

Code splitting is a technique that allows you to split your JavaScript code into smaller chunks that can be loaded on demand. This can help reduce the initial load time of your application and improve performance. You can use tools like webpack to split your code.

Lazy Loading:

Lazy loading is a technique that allows you to only load resources when they are needed, rather than loading them all at once. This can help reduce the initial load time of your application and improve performance. You can use the Intersection Observer API for lazy loading images and videos, and dynamic import for lazy loading modules.

Caching:

Caching is a technique that allows you to store resources on the client's browser so that they can be reused later without having to be downloaded again. This can help reduce the load time of your application and improve performance. You can use the Cache API for caching resources.

Optimizing images:

Optimizing images means reducing their file size without losing quality. This can help reduce the load time of your application and improve performance. You can use tools like ImageOptim or Kraken.io to optimize your images.

Using a JavaScript framework:

JavaScript frameworks like React, Angular, and Vue.js can help you build large and complex applications more efficiently. They provide a set of tools and conventions for structuring your code, which can make it easier to maintain and improve performance.

Keep in mind that performance optimization is a continuous process, you should test and profile your code regularly to ensure that it runs as efficiently as possible.