Engineering: - Infrastructure (500M MAU) - Web Dev - iOS Dev - Android Dev - Design - UX - Localization

Data: - Ranking timelines - Ad performance - Recommendations - Business analytics - R&D

Product: - Coordinating across the above 2 and adding/measuring (new) features

Sales: - Ads

Finance/HR/Admin/Accounting/Office Manager(s)/Recruiting: - Running a company

Reddit serves out a crapton of pages every day. They need a robust backend service which means you need people to maintain it.

Beyond that you have community managers, people to run AMAs, people to manage ad accounts, HR, etc... 230 people to run the one of the largest and most dynamic sites on the Internet doesn't seem out of line.