It was an assignment, not an interview. They asked me to implement two rather easy assignments in two weeks. I implemented the first one in C++ using valarray(obviously the best choice for both speed and efficiency in fast mathematics) in TDD fashion using GTest(no error is possible) and the second one in python with a semi-:KMeans clustering algorithm with acceptable efficiency and speed(enough points in less than 0.4 seconds). I sent back the solutions in two days!! I received no answers for more than 2 weeks, so I sent a follow-up email and received a very vague, unclear, Irrelevant answer: "We have received many applications for this position and I am very sorry to tell you that we cannot shortlist your application at this point. Please accept my apologies for not giving you more favorable news. We appreciate your engagement, however, we have to focus on candidates with a deeper knowledge in C++ development, python, and map creation and hence yield higher performance during an early stage. " Is it so hard to send such a nonsense answer in just two or three days?! ( I am sure the solution was good enough for them to see my depth of C++ knowledge, besides, the assignment did not involve any python and/or map creation related questions at all, even though I implemented a semi k-means clustering algorithm using python to show my python abilities) Is it so hard to be at least clear and honest about your problem with the applicant(nationality, etc.)?! or do you just need your questions to be answered to get new ideas?