Had a meeting with a PI

Just finished an interview with a PI I emailed earlier (for CS PhD), he was nice and he asked me about my research, discussed with me improvements, we were like brainstorming so it was nice. But at the end he said to me okay but I will give you a challenge and see what you can do. And we will have weekly meetings in which I update him with my progress. Is it a good sign? Like would he take me or I would just get a rejection after all that effort. I am clueless guys, would appreciate any guidance or help. Or if someone had been in this situation before.