CMS version updates, troubleshooting errors breaking site, Database tuning, Security, Backups, SSL certificates. Along with some additional custom changes in the existing extensions like LoveFactory, RSForms, Fabrik, Community Builder or be it WooCommerce.
Once your site is online,  there are further activities that need regular attention like keeping track of visitors,  check on server backups, strategy for Emergency, email issues, adding content, database tuning, analysis of visitor on site using Google analytics,  Social media updates and much more.

You may also require, to add more features to existing component and plugins. Contact me and I will be happy to help.