Isembard, a London startup that’s built a platform to help hardware makers in defence, aerospace and robotics manufacture components and more, is supercharging its efforts to build a new wave of AI-powered factories. The London startup today announced a fresh $50 million in Series A funding, only that it will be using to open 25 new “AI-powered factories” for its aerospace and defence customers.
The round includes investors from across the UK and the US — a spread that underscores Isembard’s business focus across the two countries. Union Square Ventures from New York is leading the round, with new US defence and deep tech investors Tamarack Global and IQ Capital participating alongside previous investors, London-based Notion Capital and US-based CIV, and several angels. The funding comes less than a year since Isembard announced a seed round of $9 million led by Notion.
USV is an interesting lead investor here as the VC is possibly better known for some of its consumer investments in companies like Twitter, Etsy and Twilio — although it has made a number of investments across industrial use-cases involving robotics, batteries and more.
“Isembard is redefining the process of owning and running a factory. By embedding deep operational expertise into an agentic OS, MasonOS lowers the barrier to operating high-performance manufacturing businesses and enables a networked, capital-efficient path to scale,” said Rebecca Kaden, Managing Partner at Union Square Ventures, in a statement. “At a moment when demand for advanced manufacturing is accelerating and interest in SMB ownership is rising, Isembard brings both forces together. We’re excited to partner with Alexander and his team as they expand access to factory ownership and rebuild industrial capacity across the West.”
The market for defence tech is booming right now, with nearly $9 billion raised by European startups alone in 2025 (and much more when you add in US startups). But one challenge that is growing in urgency is the “second valley of death” problem: manufacturing is hard, especially when it comes to state-of-the-art technology, and so companies that are working to address this and make it easier to build and scale are getting attention.
This is where Isembard comes in.
The startup — whose name is a nod to the British engineer and bridge builder Isembard Kingdom Brunel — has built an AI platform called MasonOS (launched at ResilienceConference in September 2025). MasonOS aims to link up hardware companies with a network of factories to specify and then produce the different components that make up their systems.
The idea is to be “just in time”, letting hardware makers scale up quickly when they need to without having to take on the expense and resource drain of building their own factories.
On the manufacturer side, there already exist large networks of machinists, typically run as smaller businesses, that can take on more work if they had visibility of it, yet many these days do not. The potential to make lots drop off in manufacturing ability and industrial muscle is something that Isembard is trying to resuscitate and strengthen.
“We’re different from a typical manufacturer because of two things. One is that we actually build our own software and that’s what our factories are running on,” Alexander Fitzgerald, the CEO and founder, said in an interview with Resilience Media last year when it was preparing to launch MasonOS. “The other difference is our business model. We’re building not one large centrifised factory, but a network of small -and medium-sized factories, doing that through a franchise business model.”
The UK and the US have long traditions in manufacturing, which means that both countries have a number of factories and machinists that are set up to fit that model.
Isembard is doing more than just working on connecting single existing factories with a variety of would-be customers. Last year, we learned that it also helped Helsing set up its new maritime facility in Plymouth. (Helsing refers to this as a “resilience factory.)
Other big names in defence tech that Isembard works with include Anduril, Tekever and ARX Robotics.
Isembard is not disclosing its valuation with this round. Its seed was at a very modest $17.6 million, per PitchBook estimates. (We’ll update the story if we learn more.)
