Wafer has raised $40 million in a Series A at a valuation above $200 million, about five months after closing a $4 million seed round in April 2026. The San Francisco-based startup, led by co-founder and CEO Emilio Andere and co-founder Steven Arellano, uses autonomous AI agents to optimize GPU workloads across chips and model architectures. In July 2026, Wafer fine-tuned Z.AI’s GLM-5.2 model on AMD’s MI355X, achieving approximately 80% of Nvidia’s B200 throughput at less than half the cost. Wafer says its system delivers 2x to 2.8x speedups over stock baselines across various open-source models, while production GPUs average about 20% utilization. The Series A was co-led by Marathon and Chemistry, according to the latest account; existing coverage identified AMD Ventures and Outset Capital among participants and described Marathon Management Partners as a co-lead. Backers include Google’s Jeff Dean and OpenAI’s Wojciech Zaremba, while earlier investors Fifty Years and Y Combinator increased their support. Wafer is targeting the software gap around Nvidia’s CUDA ecosystem through automated optimization for AMD’s ROCm stack and other heterogeneous computing environments.