Insted of copy vendor folder to hosting you just copy vendor.phar. All libraries are build in to one phar file. Better for fast FTP transfer speed. On your development machine you need to set phar.readonly=Off in php.ini to be able to build phar file.
composer install
php build.php
You need to run phar build always after composer commands to update phar file.
app - Folder with your PHP aplication. www - Folder with static files and index.php to boot app. build.php - Build script to convert vendor folder to phar file.
By default phar files are readable as normal text files. You need configure server to block this. Otherwise anybody could read source code inside phar file.
Before uploading phar to production do not forget to composer install with all optimizations and then build phar file again. For examle:
composer install --no-ansi --no-dev --no-interaction --no-progress --no-scripts --optimize-autoloader
Be aware that phar can hit your performance. Read some articles and test it with your application.