Two weeks prior to this, I had applied to a generic SW Eng role and been auto-denied by their resume screen. Applied through recruiter. Contacted by recruiter to complete two coding challenges on HackerRank. Completed these and was scheduled for a phone interview the next week. The phone discussion was comfortable and enjoyable. The interview moved very fast, which was ok for me because I typically speak fast, but if you like to take a moment or two to think that was not allotted for. There was a brief discussion of some larger networking/sys admin concept and systems. The coding portion was quite brief. The only question I did not answer as desired was the last in regards to a specific rate limiting algorithm I simply was not familiar with. I proposed a structure that would solve the problem, but perhaps not as efficiently, and I am not sure if the Interviewer understood what I meant by my answer. With the pace that was kept during the interview, it was not possible for me to clarify. However, considering we were coding and working in high level languages and concepts, I would not have thought to drop to a much lower level algorithm quickly, even if I had been familiar with it. Clearly there are some buzz words or "gotchas" that were being screened for. I've had phone screens were I have been less fluid and immediately correct in my answers that I have passed. The auto-deny on my resume but consideration by a recruiter would indicate this as well. In addition, my phone interview was scheduled as a "SW Eng, Entry Level" when it was very clearly for Site Reliability Engineer. Prepare and be comfortable in the phone screen and understand that whatever system they use to find talent may still be maturing. Twitter still holds to the old-school notion that they will not share feedback from your application and they make a point of stating this in the denial email. This practice simply continues the adversarial relationship many employees and job seekers feel in regard to corporations. It is strange that modern technology companies plucking from a high demand applicant pool would continue this practice, as providing feedback to applicants would only help them grow professionally (and not on the company's dollar) and make them more likely to reapply successfully in the future.