Esri has set up a Developer Support Repository on GitHub to support ArcGIS developers. It provides many code samples for ArcGIS developer products (e.g., Python, .NET, JavaScript, Android …), many of which are from Esri employees. These samples demonstrate various aspects of how GIS solutions can be developed for Desktop, Mobile, and Web.
Furthermore, this repository is open for code samples from the community. Anyone can share their experiences with other developers through this platform.
More information here.
