You can use excludeFiles to drastically reduce the number of files which are watched during --watch. This can be a useful way to reduce the number of open file which TypeScript tracks on Linux.
json
{
  "watchOptions": {
    "excludeDirectories": ["**/node_modules", "_build", "temp/*"]
  }
}{
  "watchOptions": {
    "excludeDirectories": ["**/node_modules", "_build", "temp/*"]
  }
}