RES Software Developer interview questions

First round was a 30-minute call with a developer and product owner. Pretty similar to a typical intial HR screening call. Reviewed work history, asked some basic behavioral questions (e.g. What type of team do you work best in?) as well as some basic technical questions (What are the main principles of OOP?), pretty informal overall. Next round was scheduled for 1.5 hours. They gave me a programming problem to solve and left me on my own to write a solution for ~45 mins. Then reconvened and had my walk through my process for coming up with as solution, as well as analyze their example solution. After that just some more going over my resume with another product manager and basic experience questions about my current and previous roles. Did not make it through to any following rounds/receive an offer after second round Interviews themselves were a pretty positive experience, however they took 2.5 weeks to contact me after the first round, and I had to reach out after 3 weeks to get a response after the second round, which is pretty frustrating and a pretty big negative to the whole experience.