Working as the only programmer on a confidential R&D game project, thus I worked at every possible subject 

Project is develop with Unity 3D and includes many low-level optimizations, architectural designs and custom implementations to achieve high performance at controlling thousands of entities even at low-mid devices

Some implementations are like : meshes created realtime, high performance terrain with tools which provides easy manipulation, editor extensions for fast and straightforward level design, multiplayer system using low-level Unity API, shaders for satisfying custom needs, 2D physics collision detection and resolving, spationing for performance boost , new inspector with c# reflection and various gameplay feature

As a side duty at the company, I successfully supervised 8-10 interns each summer, for developing fast game prototypes either letting them work individually or as a team of two (used Unity 3D and MonoGame)