​Tejas Kumar is an AI Engineer at IBM, based in Berlin, Germany. He is the best selling author of Fluent React (O’Reilly), the host of the ConTejas Code podcast, and has given 81 recorded talks at 65 events since 2012. His talk “Harnesses in AI: A Deep Dive” at AI Engineer Europe 2026 has over 275,000 views, and his talk on LLM evaluation, “Your Evals Are Lying to You”, was accepted at AI Engineer World’s Fair 2026. He is also an angel investor and advisor to early stage startups, 3 of the 6 he has backed since acquired, by CoreWeave, the Linux Foundation and Supabase.