Toni Lopez

Toni Lopez is the Chief Technology Officer at Karumi, an artificial intelligence startup developing personalized product demo agents for sales teams, based in San Francisco, California. Prior to joining this Y Combinator Fall 2025 company, he served as a founding engineer at Stack AI, another Y Combinator-backed enterprise from the Winter 2023 batch. Lopez is a three-time founder whose previous entrepreneurial ventures include co-founding and acting as the Chief Technology Officer for both Cactus AI and COME. His technical background also includes tenures as a senior software engineer at IBM Research and at Seaplane AI, a startup backed by Sequoia Capital. Additionally, he held senior engineering roles at Sparta Commodities and Pleasound. His current professional focus centers on leveraging artificial intelligence to build scalable go-to-market tools and advanced software engineering solutions for enterprise clients.