Need a developer experienced in 3d Apple game programming

I am a programmer in my spare time. I designed a simple free iOS game for Swift that is published in the Appstore and some other small apps. I am currently designing a new version of the game, it is almost ready, but I am having a few problems with it (I'm not a pro). I need a developer (Swift, XCode) to help me redesign the game. Problems include: performance, too much memory usage and associated crashes, problems with SCNScenerenderer, PhysicsContact, difficulties in implementing multiple SCNscenes.