Thank you for letting me know the links were broken. I updated the links in the post, so they should work again.

If your are using ASP.NET core, then the story has changed a lot since I published this post. I wrote an implementation of IDistributedCache that stores sessions in Firestore here: https://github.com/GoogleCloudPlatform/google-cloud-dotnet-powerpack/tree/master/Google.Cloud.AspNetCore/Google.Cloud.AspNetCore.Firestore.DistributedCache Another post will come soon.