Target Developer interview questions

I got the interview through GHC. After the coding challenge, they directly called for on-site interviews in Minneapolis, MN. There were 2 rounds. 1 technical and other behavioral. This entire process took around 3 weeks. However, after the on-site interview, they took around 5 weeks to give the result, that too, after multiple follow-ups. I got rejected because they sponsor a work visa. They had my details way before scheduling an on-site interview that I need a work visa. Still, they proceeded with the application and later rejected for the reason that they knew beforehand. Just one advice: Don't waste the candidate's time and efforts when you know you have the reason to reject them way before you call them for an on-site. If not that. at least inform them of the results within a week or so and don't test their patience by making them wait for 5 weeks.