I was contacted by an external recruiter. Then, I had one phone screen with a recruiter from the company. Following that, I completed a two-hour coding test.

Next, a software engineer contacted me and asked a bunch of technical questions he'd gathered from the internet. Nothing very original; probably all the questions he asked were among the top 50 interview questions. He was a nice guy.

Then, they invited me for an onsite interview in Houston.

The first interview was with a manager. He asked general questions about my background and some factual questions. Some of them were really stupid. I tried to answer all questions, and I think my interpretations were good. I sometimes expressed that what he was asking wasn't very meaningful because of X, Y, or Z reasons, and he accepted that.

He then asked a coding question that wasn't hard. I solved it in less than 7-8 minutes, I guess. You write code on a laptop. He looked at the code and found a test case that failed the program. I suggested two ways to fix it and then implemented the fix. He then started discussing which way was more efficient. I expressed my idea. It was related to letters. I wrote the code in Java. He asked me how I could efficiently convert an uppercase letter to a lowercase letter. I answered using a Java-specific approach.

This guy was very interested in low-level programming. He talked about a tricky way to do it. Actually, before he mentioned it, I gave an answer that was very similar to his. For some reason, he didn't like it.

Then we talked about test cases. I gave two different answers. I tried to point out that I would test boundary conditions as well as regular conditions. I suggested an automated way to test the program I wrote. He liked the idea.

He then tried to confuse me with another idea that was actually identical. He said that details are very important for the company, etc. He even went into machine code level details of the implementation. It was a weird interview. I don't really like the guy. He was obsessed with stupid tricks. Even if your answers are close to the tricks that amaze him, he doesn't like to acknowledge that you know what he's thinking. Weird guy, a type of person impossible to make happy.

Next, another guy came. He asked some questions about my background and previous work, etc. He seemed very interested in what I did before. I recently finished my PhD and talked about my dissertation. He asked me to write a binary tree, which I did. Then he wanted me to test it by printing it. I wrote a method that had a slight problem, but I solved it (he also gave an idea while solving it). I tested the tree, and everything was working.

Two guys took me to lunch at a nice place. They told me they wouldn't give any feedback and that I could ask any question I wanted. I asked questions about the company and Houston. They seemed happy to work at Two Sigma and live in Houston. They tried to create an impression that very special people work at the company. They were nice guys.

We returned to the company. The secretary came and said they didn't feel I was a good match. Then I left the company. It was a bit surprising because I wrote the code for two programming questions without any problems. The second interviewer behaved very nicely. I answered most of the first interviewer's questions, discussed a little bit, and stood by the correctness of my answers. Maybe he didn't like me because I wasn't submissive, lol.

The questions were not very difficult, but some were meaningless. Some were created for interviews, while others reflected the peculiar obsessions of the first interviewer. The most unexpected one from the first interviewer was, "What is Gödel's incompleteness theorem?" He was not normal.