SF Tensor builds infrastructure that lets AI labs focus on research rather than DevOps. Its managed platform offers automatic GPU kernel optimization across NVIDIA, AMD, and Vulkan, finds the cheapest compute across cloud providers, handles spot-instance migration, and scales distributed training from 1 to 10,000 GPUs without code changes. The founders claim the solution can cut compute costs by up to 80%. Founded by brothers Ben, Luk, and Tom Koska, the company is part of Y Combinator's Fall 2025 batch.