What should I go for?

Hi. I'm currently in 11th grade, which means I only have one year left of high school. Since time is limited, I need some guidance on the activities I should focus on to improve my chances of being accepted into an Ivy League university (I plan to major in Computer Science). So far I've had a good academic record, performed pretty decent in Olympiads and participated in various extracurricular activities. I'm also looking for internships. However, I haven't had any major leadership positions at school such as being elected president and I was wondering if such things would significantly increase my chances of admission or if it would be better to focus on achieving strong results in the national phase of the Informatics Olympiad next school year.

Any suggestions on what I should prioritize and what activities I should definitely do?

Thanks in advance!