Sunlight: The rising UK start-up that could be ‘the next VMware’

22 Feb 2021

Image: © Andrii Salivon/

Led by an early pioneer in virtualisation, Sunlight has the potential to become the gold standard in this area of tech.

In late 2020, Sunlight closed a $6m Series A funding round led by OpenOcean and Robert Bosch Venture Capital. This funding will be used by the Cambridge-based start-up to support growth in 2021.

“We’re scaling up our commercial operations. These are exciting times for us,” said founder and CEO Julian Chesterfield.

Sunlight develops virtualisation technology for data-intensive applications, such as artificial intelligence, analytics and big data.

“The need for Sunlight has arisen from the combination of cloud adoption and migration – be it public, private or hybrid – along with a growing class of hugely data-intensive applications, such as drone image processing. Data increasingly has to be processed in real time at the edge of the network at considerable costs to businesses,” Chesterfield explained.

He believes the virtualisation software most cloud services are built on is no longer fit for purpose. “It has not kept pace with the performance advances of the hardware and can no longer process data efficiently,” he said. “It is also far too bloated to run on ‘far edge’ servers in challenging environments, such as factory floors.”

That’s why Sunlight has “fundamentally redesigned this architecture,” according to Chesterfield, “with a smaller footprint than even a bare metal Linux host can achieve”.

“This means that we can run equally as efficiently on the smallest embedded mobile device ARM processor as we can on the largest Intel and AMD cloud data centre servers. In practice, this means we can run storage 10 times faster than legacy virtualisation, taking up a quarter of the compute resources and with cloud-first management capability,” he said.

“Most critically, Sunlight enables critical high-performance edge applications to run effectively, with the potential to power the whole hybrid cloud of the future.”

‘We can run equally as efficiently on the smallest embedded mobile device ARM processor as we can on the largest Intel and AMD cloud data centre servers’

If Chesterfield seems confident in his product, it’s probably because he has been at the forefront of this technology for more than a decade. He was part of the original Xen Hypervisor development team in the University of Cambridge and has worked in the cloud and virtualisation industry for more than 15 years.

In 2011, he founded and led the emerging technologies team at OnApp, a software company aiming to simplify cloud infrastructure management. It was here that Chesterfield worked alongside Paul Brennan, Kosten Metreweli and Thanassis Zografos for more than five years. “They are all now part of my management team at Sunlight,” he said.

Sunlight began as an incubation project within OnApp and was subsequently spun out as a standalone company.

“Xen became the foundation of the public cloud back in 2007, when it was adopted by Amazon and most of the emerging public cloud infrastructure providers of the day,” said Chesterfield. However, things have changed since the original Xen Hypervisor technology was developed 15 years ago.

Back then, according to Chesterfield: “The fastest peripheral storage devices only required a fraction of a CPU core to process, added to which most storage was always centralised into disk arrays and accessed remotely.”

We’ve also seen a growing a trend in hyper-converged infrastructure – a software-defined, unified system that combines all the elements of a traditional data centre.

“No one envisioned the enormous growth in high-performance flash storage technologies – particularly NVMe – and so the virtualisation platform was architected with isolated management resources in mind,” said Chesterfield.

‘Our product has the potential to be ubiquitous, powering a good proportion of next-generation clouds and edge devices’

Sunlight aims to provide a complete infrastructure for a super-high-density, high-performance cloud at lower cost and energy requirements of legacy competitors.

“We think the problem we solve is pretty ubiquitous. Data generation, processing and consumption is only going to continue to increase. Cloud and edge computing are fundamental to making that data economy work. And Sunlight offers a way to deliver the high performance required in a low-cost and energy-efficient way,” said Chesterfield.

“The world can’t keep throwing hardware at the problem! So I think we can grow Sunlight into the next VMware – the infrastructure of choice for data-intensive applications.”

The company went to market last year with a few enterprise customers. It also launched a version in the Amazon cloud. “Since then we’ve been scaling up our partner network, working through Synnex in the US and Acer’s server division, Altos, in Asia-Pacific. We’ve been working on projects that range from drone image processing using AI, through to IoT-enabled coffee machines, through to FX rendering. There’s never a dull moment,” said Chesterfield.

On the back of the Series A raise, the company hopes to go on to attract more investment. “Our product has the potential to be ubiquitous, powering a good proportion of next-generation clouds and edge devices. Being able to scale fast and get the product to market in North America, Europe and Asia Pacific is really important to us, and that requires money,” said Chesterfield.

“Building a deep-tech [start-up] is very different to building a SaaS company. It takes a lot of time and resources to build the first version of the product. This is primarily due to the complexity of the technology stack, and the need for product maturity. This makes it far harder to bring deep tech to market. Luckily I’ve been surrounded by a great team who all believe in our mission and that makes it all the more rewarding to have persevered and brought this product to market.”

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Elaine Burke is the host of For Tech’s Sake, a co-production from Silicon Republic and The HeadStuff Podcast Network. She was previously the editor of Silicon Republic.