These are my suggestions to lock things down, make a group called let's say coders.

sudo find /var/www/tts_project/ -type f -exec chmod 664 {} \;
sudo find /var/www/tts_project/ -type d -exec chmod 775 {} \;

# Assuming your web server belongs to the group called www-data, let's allow the
# ... server to modify these important folders only:
sudo chgrp -R www-data /var/www/tts_project/logs
sudo chgrp -R www-data /var/www/tts_project/configs
sudo chgrp -R www-data /var/www/tts_project/services

# So, you probably want to allow cron-jobs to run code. Let's make it executable:
sudo chown +x /var/www/tts_project/cli_cron