Have you previously developed data storage systems or created databases from scratch?

Creating a data storage system or database from scratch is a complex task that involves designing the data structure, implementing mechanisms for storage, indexing, transactions, and ensuring data integrity.

In terms of experience, most developers use ready-made DBMSs (such as SQL Server, SQLite, PostgreSQL) and work with them through ORM or SQL queries. Building your own database requires deep knowledge of algorithms, data structures, and system programming.

An example of a simple implementation of data storage in C# is serializing objects to a file:

[Serializable]
public class DataItem {
    public int Id { get; set; }
    public string Name { get; set; }
}

// Saving to a file
var items = new List<DataItem> { new DataItem { Id = 1, Name = "Test" } };
using (var stream = File.Open("data.bin", FileMode.Create)) {
    var formatter = new BinaryFormatter();
    formatter.Serialize(stream, items);
}