특이한 뒤끝서버 Json 구조를 Object로 바로 파싱하는 코드(차트만 사용 가능). Newtonsoft.Json 라이브러리를 이용해 사용

BackEndJsonUtility.cs

public static class BackEndJsonUtility
{
    public static readonly JsonConverter[] BackEndJsonConverters =
    {
        new ObjectToIntConverter(),
        new ObjectToFloatConverter(),
        new ObjectToDoubleConverter(),
        new ObjectToStringConverter()
    };

    private class ObjectToIntConverter : JsonConverter
    {
        public override bool CanWrite => false;

        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(int);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var o = serializer.Deserialize<TypeValue>(reader);
            var sValue = o.S?.ToString();

            if (!string.IsNullOrEmpty(sValue) &&
                int.TryParse(sValue, out var value))
            {
                return value;
            }

            return 0;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

    private class ObjectToFloatConverter : JsonConverter
    {
        public override bool CanWrite => false;

        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(float);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var o = serializer.Deserialize<TypeValue>(reader);
            var sValue = o.S?.ToString();

            if (!string.IsNullOrEmpty(sValue) &&
                float.TryParse(sValue, out var value))
            {
                return value;
            }

            return 0f;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

    private class ObjectToDoubleConverter : JsonConverter
    {
        public override bool CanWrite => false;

        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(double);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var o = serializer.Deserialize<TypeValue>(reader);
            var sValue = o.S?.ToString();

            if (!string.IsNullOrEmpty(sValue) &&
                double.TryParse(sValue, out var value))
            {
                return value;
            }

            return 0d;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

    private class ObjectToStringConverter : JsonConverter
    {
        public override bool CanWrite => false;

        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(string);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var o = serializer.Deserialize<TypeValue>(reader);
            var sValue = o.S?.ToString();

            if (!string.IsNullOrEmpty(sValue))
            {
                return o.S;
            }

            return null;
        }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

    private struct TypeValue
    {
        public object S;
        public object NULL;
    }
}

[System.Serializable]
public class Rows<T>
{
    public List<T> rows;
}

Usage.cs

/*
Json 구조
{
    "rows": [
        {
            "index": {
                "S": "10000"
            },
            "Name": {
                "S": "이름"
            },
            "Description": {
                "S": "구조가 왜 이래"
            }
        },
        ...
    ]
}
*/
using Newtonsoft.Json;

public List<Item> Parse(string json)
{
    var obj = JsonConvert.DeserializeObject<Row<Item>>(json, BackEndJsonUtility.BackEndJsonConverters);
    
    return obj.rows;
}