One inbox, many hands
Assign a conversation to a colleague and it leaves everyone else's queue. The assignment is visible to the whole team, which is the entire trick — duplicated replies happen because nobody can see who already picked something up.
Notes nobody outside sees
Leave an internal note on any thread. Notes are stored beside the conversation but are never included in the reply your customer receives, so you can argue about a refund in private and still sound composed in public.
Saved replies that stay current
Write an answer once and reuse it. When the underlying policy changes you edit the saved reply in one place, and everyone who uses it after that sends the corrected version. Export the full set as a PDF whenever you need to hand it to a new hire.
An API for the rest of it
Everything the interface does is available over a documented REST API, including creating conversations, attaching files and reading the full audit history of a thread. See the questions page for the rate limits.