Ocado Group Senior Embedded Software Engineer interview questions

Ocado's interview process looks very bad. This feedback resonates with other feedbacks, Big companies need to teach their employees on the interview process and communication. Phone interview was arranged through recruiter but they never called on the arranged day. So, arranged again for different day and the call came 5min delayed and the interviwer didn't apologize that means neither the HR conveyed that they should mention the apologies nor the interviewer knew anything about it. It was general screening on knowing things from the resume and went well as I answered honestly on what I knew. Interviewer mentioned that they will give feedback to HR. Even after weeks there is no feedback, recruiters are chasing but still no feedback... Even if there are large applications, is Ocado doing phone screening for everyone? Moreover, this screening was for "Senior" engineer and how many of them were given feedback god only knows.