RedisReadTopUsers.cs

public class UserWithPostCount
{
    public int ID { get; set; }
    public string Name { get; set; }
    public int PostCount { get; set; }
}

public IEnumerable<UserWithPostCount> ReadTopUsers(int offset, int countCategories)
{
    var cache = _muxer.GetDatabase();
    var topUsers = cache.SortedSetRangeByRankWithScores("UsersByPostCount", offset, offset + countCategories - 1, Order.Descending);
    var ret = new List<Dto.UserWithPostCount>();

    var keys = new List<RedisKey>();
    foreach (var e in topUsers)
    {
        string redisId = e.Element.ToString();
        keys.Add(new RedisKey(redisId + ":Name"));
    }

    var names = cache.StringGet(keys.ToArray());
    for (int i = 0; i < names.Length; i++)
    {
        int.TryParse(topUsers[i].Element.ToString().Substring(5), out int id);
        ret.Add(new Dto.UserWithPostCount { ID = id, PostCount = (int)topUsers[i].Score, Name = names[i] });
    }

    return ret;
}