Program.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;

namespace ConsoleApplication1 {
    class Program {
        static void Main(string[] args) {
            const string response = @"
                {
                    contacts: [
                    {
                        type: ""email"",
                        value: ""hello@world.com""
                    }, 
                    {
                        type: ""cell"",
                        value: {
                            code: ""+7"",
                            number: ""9779998877"",
                            countryId: 123
                        }
                    },
                    {
                        type: ""vk_id"",
                        value: 12342341
                    }]
                }
            ";

            var resume = JsonConvert.DeserializeObject<Resume>(response, new ContactConverter());

            Console.WriteLine(JsonConvert.SerializeObject(resume,
                new JsonSerializerSettings {
                    Formatting = Formatting.Indented
                }
            ));
        }
    }

    public class ContactConverter : CustomCreationConverter<IContact> {
        public override IContact Create(Type objectType) {
            throw new NotImplementedException();
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) {
            var jObject = JObject.Load(reader);

            var target = CreateContact(jObject);

            return target;
        }

        /// <summary>
        /// Create concrete contact base on contactType value
        /// </summary>
        /// <param name="jObject"></param>
        /// <returns></returns>
        private IContact CreateContact(JObject jObject) {
            var contactType = (string)jObject.Property("type");
            var json = jObject.ToString();

            switch (contactType) {
                case "email": {
                    return DeserializeObject<EmailContact>(json);
                }
                case "cell": {
                    return DeserializeObject<PhoneContact>(json);
                }
                case "vk_id": {
                    return DeserializeObject<VkContact>(json);
                }
                default:
                    throw new NotSupportedException("Unexpected contactType: " + contactType);
            }
        }

        private T DeserializeObject<T>(string json) => JsonConvert.DeserializeObject<T>(json);
    }

    public class Resume {
        public IList<IContact> Contacts { get; set; }
    }

    public interface IContact {
        string Type { get; set; }
    }

    public class EmailContact : IContact {
        public string Type { get; set; }
        public string Value { get; set; }
    }

    public class PhoneContact : IContact {
        public string Type { get; set; }
        public PhoneContactValue Value { get; set; }
    }

    public class VkContact : IContact {
        public string Type { get; set; }
        public int Value { get; set; }
    }

    public class PhoneContactValue {
        public string Code { get; set; }
        public string Number { get; set; }
        public int CountryId { get; set; }
    }
}