The following class implements example serialization routines for serializing simple types used throughout these samples.

public static class SampleSerializationExtensions
{
    /// <summary>Extension method on System.Decimal to convert to byte[16]</summary>
    public static byte[] GetBytes(this decimal value)
    {
        int[] ints = decimal.GetBits(value); //int[4]
        byte[] bytes = new byte[16];
        Buffer.BlockCopy(ints, 0, bytes, 0, 16);
        return bytes;
    }

    /// <summary>Extension method on byte[] to convert to System.Decimal</summary>
    public static decimal ToDecimal(this byte[] value)
    {
        if (value == null) throw new ArgumentNullException(nameof(value));
        if (value.Length != 16)
            throw new ArgumentException("Expecting byte[16]", nameof(value));

        int[] ints = new int[4];
        Buffer.BlockCopy(value, 0, ints, 0, 16);
        return new decimal(ints);
    }

    /// <summary>Extension method on System.DateTime to convert to byte[8]</summary>
    public static byte[] GetBytes(this DateTime value) =>
        BitConverter.GetBytes(value.ToBinary());

    /// <summary>Extension method on byte[] to convert to System.DateTime</summary>
    public static DateTime ToDateTime(this byte[] value)
    {
        if (value == null) throw new ArgumentNullException(nameof(value));
        if (value.Length != 8)
            throw new ArgumentException("Expecting byte[8]", nameof(value));

        return DateTime.FromBinary(BitConverter.ToInt64(value, 0));
    }
}