Flow Engineering raises $50M to keep complex hardware designs aligned

Flow Engineering builds requirements and verification software for engineers developing cars, aircraft, rockets and other complex hardware. The platform connects design requirements with CAD files, simulations, code and test results so a change in one place does not disappear into another team’s tools. The company announced a $50 million Series B at a $750 million valuation on Sept. 30.

The hard part isn’t generating another design. A change to a vehicle or spacecraft can affect mechanical, electrical and software systems at once, while each team must show that the updated product still satisfies technical and regulatory requirements. Flow’s agents monitor those artifacts, trace the downstream effects, flag conflicts and check requirements and test coverage.

That makes Flow a coordination layer around existing engineering tools, rather than a replacement for every CAD package or simulator. The company describes the platform as a living record of how requirements, designs and tests connect; engineers can then see what else needs review when an artifact changes. The workflow matters most in programs where a small edit can create failures several systems away.

Flow names Rivian, Anduril, Joby Aviation, Stoke Space, Astranis and Radiant Industries among its customers. It says additions since its previous round include RV Tech, the Rivian-Volkswagen joint venture, and General Motors PPU. The company also says usage at Rivian grew from 40 to 1,500 people in seven months.

Valor Equity Partners and Atreides Management co-led the round, while Sequoia Capital participated and former Sequoia partner Roelof Botha joined Flow’s board. Flow plans to expand its review, branching and evaluation features, hire AI and systems engineers, pursue FedRAMP authorization and grow sales. Its proposed reduction of hardware iteration cycles from months to days remains a company target.