iOS developer with video playback experience

The client has a successful iOS app that mainly deals with video playback and is looking for a iOS/Swift developer with lots of experience with this topic (ideally also with RXSwift and the video component PlayerView). The freelancer should spend some days with the client's lead developer to review the implementation of the video player, profile it to increase efficiency (the current player drains the battery quickly) and suggest some caching techniques to improve the user experience when watching the feed.