I am launching a Wordpress eCommerce platform in the form of a marketplace to sell courses, appointments and events... what are the security and scalability challenges do I need to look at? Using Wordpress, Buddypress, custom events and courses plugins.. any advice on where I can hire talent?
For a small/medium-sized project WordPress might be acceptable. However, if you plan to scale up and expect a lot of traffic it will be quite difficult to keep up.
Security of WP has improved in recent years, however, it still relies in PHP one of the languages that historically has suffered of prevalent security issues.
Scalability will be difficult at some point, you will need professional infrastructure to get a lot of transactions and other operations smooth. I would recommend research dedicated eCommerce platforms, remember Wordpress was originally conceived as a blogging platform.