I can't speak for the UI, but here's how the backend is going.
The API was initially built using .NET Framework, which only works on Windows. We more or less completed the API to the point where all that was left was testing. The issue we ran into back in September was with the hosting requirements to run a Windows server were prohibitively expensive. As a result, we started a migration to .NET Core, which is cross-platform. We migrated most of the controllers to .NET Core and are currently trying to figure out authentication on the new platform.