EC Help?

Hi all,

I am currently a rising senior in California. I’m majoring in Computer Science, and I am curious to know if there are any last minute application boosting things I should do. My current ECs are listed below:

  1. Karate Junior Black Belt for 8-9 years. Went to many regional tournaments, won gold in one of them
  2. Over the summer, volunteered at my local library for about 20 hours
  3. Member of Key Club (a volunteering school club), volunteered for about 20-40 hours
  4. USACO Silver. (silver division of a CS computing olympiad).

I am considering creating a website that teaches small children the basics of coding (to essentially introduce them to CS). Is this necessary, or are my current ECs satisfactory? Keep in mind that I am not aiming for Ivy Leagues or super selective schools (like UCLA or UCB), but instead for great/elite schools like NYU, UC Davis, and UCSB.

Thanks for all your help.