Lightspeed Senior Backend Engineer interview questions

The usual HR plus two technical challenges, identical, that I would find easy even for a junior (the only real challenge being, you will write code on a dark notepad, be carefull to use a very big screen unless you want, like me, to have a space for coding equivalent to a smartphone). I failed the second one, which is not the problem. Problem is, could you please write a mail saying: 'you failed, it happens, you can now move on' ? Extremely kind, until they are rude.