Flux Raises $37M to Build the First AI Hardware Engineer for PCB Design

Flux just secured $37M in fresh capital, a $27M Series B led by 8VC, with participation from Bain Capital Ventures, Liquid 2 Ventures, and Outsiders Fund, plus a previously unannounced $10M Series A led by Outsiders Fund and co-led by Bain Capital Ventures. That is real conviction from real operators. When firms like 8VC and Bain Capital Ventures double down, they are not window shopping. They see a category taking shape.

Congratulations to Matthias Wagner, Founder and CEO of Flux, and the entire team in San Francisco. Crossing 1M sign-ups is not a vanity metric when you are rebuilding the pipes of hardware design. It is a signal that engineers are hungry for something better.

Flux calls itself the AI hardware engineer. Not a plugin. Not a sidekick. The engineer. In a single browser tab, a user can move from a natural language prompt to a manufacturable printed circuit board. That is not marketing poetry. That is a workflow shift. Planning layouts, sourcing components, testing designs, managing supply chain variables. The AI is trained on hundreds of thousands of real-world designs and fine-tuned for the jobs engineers actually need done. Less tab switching. Less guesswork. More shipped product.

The old guard of electronic design automation built powerful tools, but they were desktop-bound and workflow-fragmented. Flux is cloud-based, collaborative, and agentic by design. It treats hardware like modern software teams treat code. Shared, iterative, alive. When over 1M users raise their hand and say yes to that model, you pay attention.

The $37M is not just fuel. It is intent. The capital will push Flux into more complex electronic use cases and deepen the capabilities of its AI hardware engineer. Complexity is where margins and moats live. If Flux can handle the hard boards, the intricate layouts, the cost and supply chain trade-offs in real time, it stops being a cool tool and starts becoming infrastructure.

Investors like John Lilly and Tom Preston-Werner backing the company adds another layer of signal. Builders who scaled platforms recognize when a new platform is forming.

Hardware has always been gated by cost, expertise, and friction. Flux is compressing that curve. When you reduce the distance between idea and manufactured board, you do not just speed up engineering. You widen the circle of who gets to build.