How deep tech startup Hartley Ultrafast secured its pre-seed target through ThatRound

Hartley Ultrafast builds optoelectronic computing systems that collapse the gap between thought and reaction, bringing intelligence to light speed.

By fusing the communication power of photons with the computing precision of electronics, Hartley Ultrafast is creating a new class of hardware for ultra-low-latency AI inference and data processing.

Their technology pushes the limits of physics to deliver complex models within one nanosecond, resulting in significant energy savings, all possible with existing tech. With 100x faster interference and 1000x faster optimisation, they’re transforming performance across sectors like finance, telecommunications, data centres, industrial automation, and healthcare, where every microsecond counts.

Ready to come out of stealth mode, they recently launched their company’s rebrand at Microelectronics UK 2025, unveiling the new name Hartley Ultrafast alongside its demonstrator machine, Babbage.

The launch signalled the company’s evolution from research project to commercial deep tech player ready for investment.

Finding the right investors, faster

The Hartley Ultrafast team faced a familiar challenge: fundraising velocity. If only raising a round moved as fast as light too! But unfortunately the process of identifying relevant investors, especially those who understand technical frontiers like photonics and microelectronics, can be slow and fragmented.

However, with ThatRound’s partner network, Hartley Ultrafast secured its pre-seed target in just six weeks, with investment from both Sowing Capital and OVC Ventures, alongside their lead investor a Silicon Valley early stage VC, Strange Ventures.

“The ThatRound platform helped us accelerate our raise — we closed £500k of our pre-seed in just under a couple of months. The ability to easily find, compare, and apply to different investor syndicates and angel groups saved us enormous time and energy. Instead of getting lost in the fragmented fundraising market, we could focus on building the business while ThatRound streamlined the investor access for us."

— Josh Silverstone, Founder & CEO, Hartley Ultrafast

Focusing only on a curated network of fundraising partners allowed them to:

• Close their round faster
• Find multiple strong partner fits
• Have more time for product and commercial focus

Securing quality deal flow for investors

And for the funding partners? ThatRound’s deal flow reduced discovery time and surfaced an investor-ready startup to those who were the right fit.

Sowing Capital and OVC Ventures are the angel syndicates that invested, both with a focus on backing early-stage startups at the pre-seed and seed stages. Each of these are funding partners on ThatRound’s platform, where their syndicate lead manages the deal flow and presents only qualified deals to their angel investors, using ThatRound as a trusted source of high quality deals.

"Hartley represents exactly the kind of opportunity we look for: a high-conviction, asymmetric opportunity backed by exceptional IP and a world-class team. The speed and exclusivity of the round reinforced our belief that this is a business with real momentum. We’re excited to support them as they take on their first beachhead market and scale from there."

— Harrison Faull, Managing Director of OVC Ventures

A breakdown of ThatRound’s process

So what was the process from sign up to investment?

• Firstly, Hartley Ultrafast created their ThatRound Pitch Page on the platform, disclosing details such as sector, round size, valuation and equity offered.
• Once this was reviewed and approved, they were shared a list of the most relevant funding partners for them — based on both the partner’s and startup’s requirements.
• From that list, they could select which partners to apply to, which then granted the chosen partners access to view the Hartley Ultrafast Pitch Page.
  This approach allows startups to confidently raise in stealth mode, without the need to showcase their Pitch Page to every partner on the platform.‍
• After reviewing the startup, the interested partners were then able to accept, message and book calls directly with Josh.

"We were hugely impressed by both the scale of the opportunity and the calibre of the team. Accelerating compute efficiency isn’t just a trend—it’s a necessity in a world where AI and crypto are consuming unprecedented amounts of power.

We see photonic computing as a foundational layer of the next wave of infrastructure, bridging the gap to quantum and enabling chips to run at speeds several orders of magnitude faster than today. Backing Josh and his team felt like the smartest way to gain exposure to that future.”

— Bradley Jones, Syndicate Lead at Sowing Capital

Lessons for early-stage deep tech founders

Fundraising in deep tech at the early pre-seed stages is notoriously slower. Many investors shy away from long paths to revenue or layers of technical risk. And deep tech ventures can take years to validate, making early-stage commitment harder to come by.

Hartley’s success proves that using ThatRound, a specialised, curated platform built to help founders secure funding, can seriously tilt the playing field. What would normally take many months of outreach and diligence was compressed by targeted matches.

For early-stage deep tech founders, the lessons are:

• Don’t expect the same timeline as B2B SaaS or consumer tech. The benchmark is often 3–6 months just to secure seed funding.
  
• Investor fit matters more than volume. Deep tech raises need domain expertise and patience. Platforms like ThatRound bridge the gap between technical founders and capital-ready investors.‍
• You need to close quickly once traction is visible. Momentum acts as a signal in deep tech rounds.‍
• Infrastructure for match & discovery is a game changer. Without friction-reducing tools doing the leg work for them, many deep tech founders drown in admin, not innovation. Not forgetting that a transparent, data-driven approach builds trust on both sides of the table.

Hartley Ultrafast’s story proves that early-stage deep tech founders don’t have to choose between building and fundraising.

ThatRound is building the infrastructure to make that the norm, so the next generation of founders can spend less time chasing capital and more time focussed on building.