Download blob storage and return Json object

Please reset the stream's position to 0 after reading the blob into the stream. So your code would be:

        using (var stream = new MemoryStream())        {            blob.DownloadToStream(stream);            stream.Position = 0;//resetting stream's position to 0            var serializer = new JsonSerializer();            using (var sr = new StreamReader(stream))            {                using (var jsonTextReader = new JsonTextReader(sr))                {                    var result = serializer.Deserialize(jsonTextReader);                }            }        }

Both the question and accepted answer start by copying the entire stream into a MemoryStream which is effectively a big byte array in memory. This step is unnecessary - it's more memory-efficient to stream the blob data directly to the object without buffering the bytes first:

using (var stream = await blob.OpenReadAsync())using (var sr = new StreamReader(stream))using (var jr = new JsonTextReader(sr)){    result = JsonSerializer.CreateDefault().Deserialize<T>(jr);}

In case you don't care for streaming and want a short and concise way:

var json = await blockBlob.DownloadTextAsync();var myObject = JsonConvert.DeserializeObject<MyObject>(json);