Yeshiva University students host their fourth annual hackathon, beginning at 8:30 p.m. and running through Sunday at 8:30 p.m., in the Heights Lounge on the Wilf Campus, 515 West 185th St. The forum is for observant Jews to connect, brainstorm, and partner to build anything from apps to code for robots, in a 24-hour window. This year’s event focuses on giving back by developing creative ways to use technology to help the Jewish community. There will also be a nonprofit fair.