Using a Team to Maintain/Develop a WordPress site?

What is the best way to team develop a site with WordPress? Ideally, I’d like to have 2 people work in their own sandbox areas and then be able to move just the portions of the site they’ve modified out to the pubic site. Is this even possible?

I’m trying to effectively optimize the skills of the team and to work in parallel where possible. So if 2 people are working to design and customize 2 different pages of a website, I’d like them to not be dependent on each other to update the site. The only options I see are to have both work in the same sandbox area, or to only have one person making changes to the site at the same time.

I’m new to WordPress, but not new to large-scale project development, so I feel like there must be some solutions for WP to enable solid team development.

Thanks so much for your help.