X Software Engineer - Tweetdeck - London interview questions

Very negative experience. Reached the final on-site stage, after which I was told that I will know the outcome by the following week. As I had other offers outstanding, I made it clear to the Twitter recruiter that I need to know as soon as possible. However they got back to me a MONTH after the interview saying that they will not proceed with an offer. I asked for more detailed feedback but no one replied to my email. I spend half a day at their office, meeting multiple people, having multiple interviews, did a video interview, a coding test, and literally got no feedback at all. Very unprofessional. Stages: - Recruiter phone screening - Technical 1 hour video interview with an engineer of the team - Coding challenge, to do at your own time (of easy-average difficulty) - On-site interview. Three 1-hour sessions, including system design, coding and cultural fit