I was contacted by a recruiter after my third application.

They set up a typical HR phone screen to discuss the job and my background. The recruiter seemed new to their role and simply read directly from the job description, asking scripted questions without properly introducing themselves. They didn't seem knowledgeable about technology and couldn't answer any of my questions about the position beyond what was listed on the job description. I initially thought it might have been an intern conducting the call.

I was then moved to the next stage for an approximately one-hour technical HackerRank screen.

The technical screen began with very brief introductions and moved straight into coding without any behavioral questions, unlike what others here have reported receiving. I'm unsure if I didn't pass an initial "vibe check" and thus they decided to skip the behaviorals, or what.

I was asked two questions that were around LeetCode medium difficulty.

The first question, I initially misunderstood; it was to find the Fibonacci sum, but I thought it was just the regular Fibonacci sequence until I was corrected. I ended up solving it in O(n) time after some fumbling. The interviewer asked if there was a faster approach, to which I replied that I didn't think so. I looked it up after the interview and found there is an O(log(n)) solution that involves recognizing a mathematical trick, but I doubt anyone who doesn't already know the answer going into the interview would recognize it. I believe this question was poorly designed and lacks real-life application for the average developer.

The second question offered two possible approaches. I explained how I would implement the slower O(n) brute-force method and stated its runtime, then proceeded to code the faster O(log(n)) binary search approach. I got the faster approach correct, with one mistake that I fixed after a hint from the interviewer. I had written some test cases before fixing the mistake, and they all passed, so in hindsight, I was missing a single edge case. The interviewer made some attempts to guide me to recognize the missing test case, but I think the stress of the interview situation and their hints being a bit too vague for me to grasp caused me to miss it. I was quite hard on myself about that, only realizing it an hour after the interview concluded, but I hoped they might overlook a minor mistake and offer me a chance at an onsite interview (that's why we work in teams, right? to help catch mistakes?).

Unfortunately, I received a rejection email the next day. It's disappointing to be rejected for not knowing a specific problem beforehand or for not being perfect on another problem within a 40-minute interview, but I suppose it is what it is :(

Fibonacci sum and a modified binary search.