Optimization

#Composer's autoloader map

composer install --optimize-autoloader --no-dev

#Configuration Loading

Be sure that you are only calling the env function from within your configuration files.
Once the configuration has been cached, the .env file will not be loaded and all calls to the env function for .env variables will return null

php artisan config:cache

#Route Loading

php artisan route:cache

#View Loading

php artisan view:cache