You can now customize the memory and maximum execution duration of your Serverless Functions, or assign a custom runtime, by using the new `functions` configuration property in your `vercel.json` file. This feature is only available when using Git Integration or Vercel CLI, and allows you to adjust default behavior for functions deployed after November 8th. The `functions` property can be used to customize memory settings, maximum execution duration, and even assign a custom runtime from a list of officially supported languages or Community Runtimes provided by third-party developers. This change is part of several features planned to support advanced use cases of Serverless Functions on Vercel.