Andreessen Horowitz Leads $500 Million Series B for Nexthop AI

Venture capital firm Andreessen Horowitz (a16z) announced today that it has led a $500 million Series B investment in Nexthop AI, a networking startup designed to build high-performance infrastructure specifically for the artificial intelligence era. The round includes participation from Lightspeed Venture Partners.

As hyperscalers rapidly expand their AI clusters, traditional networking hardware is increasingly viewed as a primary bottleneck. Modern AI workloads, including both training and inference, are massively distributed and require thousands of GPUs to communicate constantly at high speeds.

Nexthop AI aims to solve this by building high-performance Ethernet switches designed natively for AI traffic patterns rather than general cloud traffic. Key features of their approach include:

Native Co-Design: Hardware and software are co-designed to meet the demands of AI-scale networks.

Open Architecture: The company's products are purpose-built for cloud providers running open-source operating systems, allowing hyperscalers to integrate and extend the architecture within their own environments.

Advanced Network Functions: The platform provides integrated software for telemetry, congestion control, and load balancing.

Nexthop AI is led by Anshul Sadana, a former executive at Arista Networks who spent over 15 years helping define the previous era of data center networking. The a16z investment team noted that Sadana’s deep relationships with hyperscalers and technical expertise position the company to become a generational leader in the field.

The investment comes as the industry moves toward faster networking standards, including 1.6 terabits/second, and navigates new design requirements for both air-cooled and liquid-cooled environments. With data center switching costs and engineering complexity increasing, Nexthop aims to provide the specialized hardware required to maximize GPU output as cluster sizes grow.