Oscar Karlströmer is Co-Founder and CFO at Zaplar (YC S26), an AI-native operating system built to automate and streamline hotel operations across bookings, communications, events, and more.

Oscar co-founded Zaplar alongside Axel Andersson Lingbert, Douglas Solberg, and Jon Milles, forming a focused team of engineers and researchers driven by a conviction that great hotels are made by people, not administration.

Oscar has demonstrated a hands-on, relationship-first approach to building Zaplar, personally engaging with hoteliers and documenting insights through a public blog series including profiles on General Managers across Sweden.

Zaplar was accepted into Y Combinator's Summer 2026 batch and raised $820K from Y Combinator, Nyman Holding, and Michael Ingelög, validating its approach to replacing fragmented legacy hotel software with a single agentic platform.

Zaplar consolidates the 5-15 separate tools the average hotel relies on into one AI-native system, enabling autonomous hotel operations and freeing staff to focus entirely on delivering exceptional guest experiences.