Optiver Software Engineer interview questions

As a first step, they have an online scheduler so you can set up your phone interview date and time. You will then be tasked in talking with HR, that didn't call on the appointed date, but one day later. She then tried spin it into "I hadn't noticed it was not today" (as if it were not her full-time job to do tens of these interviews per week), and didn't even bother to offer an apology for it. The conversation was the typical HR blablabla. They then set up a HackerRank homework assignment, involving theoretical OO questions and a couple of algorithmic exercises. The next stage involved talking with yet another HR guy for 45min and finally having another interview with a Software Engineer manager. There would have been then an "on-site" stage, but it turns out they're looking for you to guess what kind of questions you should have asked to demonstrate your motivation to work for a company that for all purposes at this point you still don't know anything about. They hire for the company, not for the team, so I really wonder what could I have asked that was specific enough to be of any worth at this stage of the interview process. As the company is large and teams (from what was described to me) have very different workflows, that's only something you could ask when talking with actual prospective team members. But oh well..