C#

Try to follow standard C# naming conventions when applicable
https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/naming-guidelines

Except for constants... For constants prefer UPPER_SNAKE_CASE.

Examples

// Interfaces
public IThingService
{
    Task<Thing> GetAThingAsync(int thingId);

    void DoTheThing(int thingDoingAmount);
    Task DoTheThingAsync(int thingDoingAmount, CancellationToken? cancellationToken = null);
}

// Classes
public class ThingService
{
    private const string THIS_IS_A_CONSTANT = "I am a constant!";

    private readonly IThingRepository _thingRepository;

    public int ThingsDone { get; private set; }
    private bool _isDoingOtherThings;

    public ThingService(IThingRepository thingRepository)
    {
        _thingService = thingService;
    }

    public void DoAThing()
    {
        if (!_isDoingAnotherThing)
        {
            ThingsDone++;
        }
    }

    public async TasK DoAnotherThing()
    {
        _isDoingOtherThings = true;
        await ExecuteVeryImportantBusinessAsync();
        _isDoingOtherThings = false;
    }

    private async Task ExecuteVeryImportantBusinessAsync()
    {
        await Task.Delay(1_000);
    }
}