Send files to Arduino SDCARD with C#

Hi guys, as the title says, I want to ask you, which method is more reliable to send files handled by a program written in C# to an Arduino UNO with Ethernet Shield (+SDCARD) through the Ethernet? I did some practice to send data via Ethernet, but i noticed that sometimes, the data that arrives to Arduino is broken (mostly when I send data very quickly). All I want to do is to send some files, plain text (something like DATA.DB, USER.DB and so on) via Ethernet, and store that data to the SDCARD (i do not want to use that data with Arduino, but I want to ask back that data, receving from Arduino to my program in C#). I saw some people that do this simply sending byte by byte... but i don't know if there something "better". Thank you.

EDIT: maybe there is also a way to send that files without opening them, I repeat: I don't want to use this file on arduino, just store to SDCARD. Please help!

TinyWebServer includes an example sketch to do file upload to the SD card. https://github.com/ovidiucp/TinyWebServer

I guess you'll find tutorials on the web how you can do Web file uploads using C#, don't you?

Oh nice, seems that will works :D Thank you. In the meantime I wrote this, seems to work that too, but as I said... this don't like to be reliable I think :\

EthernetServer server(8888);
EthernetClient client;
SdFile database;
const char* db = "DATA.DB";

void setup()
{
// All the stuffs needed
}

void loop()
{
    client = server.available();

    if (client) 
    {
        if(!database.open(db, O_WRITE | O_CREAT)){ Serial.println("ERRORE SDCARD"); return;}

        while (client.connected())
        {
            if (client.available()) 
            {
                data = client.readStringUntil('#');
                database.println(data);
                Serial.println(data);
            }
        }

        delay(10);

        database.close();

        client.flush();
        client.stop();
    }

}

EDIT: the sharp character is sent by the program (a quick way to understand when a string ends..)