The DeveloperWeek SF Hackathon, the largest challenge-driven hackathon in the U.S., took place in San Francisco over the weekend of February 23rd-24th, gathering hundreds of developers, designers, and entrepreneurs to tackle technical challenges with the aid of sponsor-provided technologies. Participants formed teams to create diverse projects, from web and mobile apps to algorithms and data visualizations, with all prizes linked to the effective use of sponsor technologies. Clarifai, an official sponsor, provided open access to its computer vision APIs, which were used in over 30 final applications, including three of the top five finalist projects. The event concluded with rapid project pitches and awards, and Clarifai's engagement allowed them to receive direct user feedback. The hackathon offered ample food and caffeine, and judges evaluated projects based on progress, concept feasibility, and potential for startup viability.