Integer Consulting Software Developer interview questions

The interview process was in a multiple stage process . The stages were the first with HR, than with a group of engineers, the last one it was with the final client.

First call with the HR, very common. They told me they had a job for Android Developer, we agreed about values and moved forward. Then they sent me a code challenge that takes to 2 hours. Two days later I finished the code challenge. I waited one week for any response and nothing, It took me two messages and one more week to finally receive a feedback from the HR. Apparently there wasn't any open opportunity for Android, and I did the code challenge all in vain.