How Raspberry Pi Became the UK's Best-Selling Computer and a Billion-Pound Public Company

What Does It Take to Build the UK's Best-Selling Computer from Scratch?

Liz Upton grew up in a mixed British-Chinese family in the UK. Her school was a strict evangelical Christian girls' boarding school with two sciences on the curriculum and a maths teacher she stopped attending. Most of what she learned came from library books and boyfriends who taught her soldering. She got into Cambridge to read Law, met Eben Upton at university, and after a brief rebellion as a professional singer for Vangelis and Rick Wakeman recordings, ended up in food and travel journalism. By the late 2000s she was one of the top three UK food bloggers by traffic, co-authored a bestselling National Geographic book, and was ghosting for cruise companies in exchange for holidays she could write about.

In May 2011 the BBC's Rory Cellan-Jones blogged about a hand-soldered prototype Eben and David Braben had built in Cambridge. The video went viral. She told Eben he had to actually do this now, and agreed to come on for six months to run press and social. She stayed 14 years. She wrote a daily development diary blog through the run-up to launch. On 29 February 2012 they pressed the launch button with 2,000 units on a pallet in Jack Lang's garage and took 100,000 orders on day one. Two OEM licensing partners, Farnell and RS Components, made and distributed the boards from a Sony factory in Pencoed. Liz and Eben mortgaged their houses to get there. They took no venture capital. The Foundation, a UK charity that owns more than 50% of the trading company, funded the education work Liz built into the business, including 300,000 young people now in weekly Code Clubs worldwide.

Raspberry Pi was supposed to IPO in 2020. The pandemic closed the market. They started again from scratch and floated on the London Stock Exchange on 11 June 2024 at £541.6m, making Liz one of only three women in Europe to have IPO'd a company she founded that year. She left five months later because the company had become, in her words, professionalised, and she missed being face-down in a spreadsheet ten different ways. She is now CEO of Negroni Venture Studios in Cambridge, chair of OLO Robotics in Sheffield and Coherence Engine in quantum computing, and one of the most vocal public advocates for UK listings, regional capital and honest conversations about money.

GUEST BIO

Liz Upton is co-founder of Raspberry Pi and served as Chief Marketing and Communications Officer from 2011 to November 2024. Raspberry Pi listed on the London Stock Exchange in June 2024 at £541.6m, making Liz one of only three women in Europe to have IPO'd a company she founded that year. She is CEO of Negroni Venture Studios in Cambridge, chair of OLO Robotics and chair of Coherence Engine, and an Honorary Fellow of The National Museum of Computing

Agenda:

• Cold open

• Introduction

• Growing up in a mixed British-Chinese family, evangelical Christian girls' boarding school

• Cambridge and the finals notes anecdote

• Rebellion: singing for Vangelis and Rick Wakeman

• Coming back to Cambridge, starting food writing

• Meeting Eben, the food blog, and building a portfolio through journalism

• Boyfriends, soldering, and inter-library loans

• The Cellan-Jones BBC video and the six-month deal that became fourteen years

• Community: blog, forums, Twitter, Maker Faires

• Mortgaging the house and oversized risk tolerance

• The success disaster: 2,000 units, 100,000 orders

• Transparency and the mag jack transistor crisis

• The Foundation as majority owner and the dividend model

• Scaling to IPO with about 110 people and 10x engineers

• The pandemic supply crisis and having a baby in lockdown

• The IPO that was supposed to happen in 2020

• Three women in Europe to IPO in 2024

• Millionaire, not billionaire

• Why London beats New York for listings

• Getting UK retail investors into the market

• Leaving Raspberry Pi and what came next

• Negroni Venture Studios and the cocktail-recipe website

• Chair roles at OLO Robotics and Coherence Engine

• Robotics today is a Palm Pilot, we're aiming for the iPhone

• Quantum sovereignty in the UK

• AI, Claude, and the Finnish company diligenced in 20 seconds

• Quickfire: one word, AI good or bad, money or passion

• What AI does to the junior programmer pipeline

• A ten-year-old's question about robotics in schools

KEY TAKEAWAYS

• Community and Openness Drive Grassroots Virality: Early adoption relied on a transparent daily developer blog, active forums, and genuine community engagement, which turned early customers into invested brand advocates.

• Business Model Hacking Over Capital Intensity: Instead of raising heavy venture capital or attempting to finance global manufacturing internally, Raspberry Pi licensed production to large original equipment manufacturers (OEMs), allowing them to scale to millions of units profitably from day one.

• Extreme Risk Tolerance as an Enabler: Taking existential personal risks—such as mortgaging homes to fund initial production—requires high risk tolerance, but it allowed the co-founders to retain complete strategic control without early investor dilution.

• Vertical Ownership Drives Long-Term Value: Controlling as much of the core stack as possible—from custom silicon and chip design to manufacturing partnerships and software—creates defensive moats and capital efficiency, even through severe supply chain disruptions.

• AI Accelerates Due Diligence & Technical Productivity: AI models like Claude radically streamline due diligence by instantly surfacing red flags across foreign-language records, while enabling experienced programmers who understand formal logic to build software faster.

• Entrepreneurship is Fundamentally Logistics: Success hinges less on grand vision and more on operational discipline, meticulous planning, and having highly organized team members to manage execution details.

Memorable Quotes

“I said, okay, fine, I'll come on for six months. I've got more interesting things to be doing. And I stayed for fourteen years.”

“We had 2,000 devices. We got a hundred thousand orders. With two thousand to sell.”

“I'm a millionaire, not a billionaire. I don't have to worry much for the rest of my life. I get to muck around doing this sort of stuff.”

“We mortgaged our houses. We thought we had a great idea.”

“One of the reasons I've been successful is that my approach to risk is a little bit mental.”

“For a child, flashing an LED on and off is much more compelling than changing a pixel on a screen.”

“There isn't actually any sort of gap in valuations between the UK and the US. We have a national habit of talking ourselves down.”

“We're so shy about talking about money, and it holds people, especially women, back.”

“One word for entrepreneurship? Logistics.”

“On paper it looked amazing. I set Claude on it, and within 20 seconds it came back flashing red. Don't touch this thing with a barge pole.”

Resources Mentioned

• Companies: Raspberry Pi (LSE:RPI), Raspberry Pi Foundation, Broadcom, Farnell (Element14), RS Components, Sony UK Technology Centre (Pencoed), Arm, Lansdowne Partners, OLO Robotics, Coherence Engine, Negroni Venture Studios, Frontier Games, Anthropic (Claude)

• People: Eben Upton, Rory Cellan-Jones, David Braben, Jack Lang, Pete Lomas, Alan Mycroft, Rob Mullins, Emma Ormond, Ben Nuttall, Nick Thompson (OLO), Robin Sterling (Coherence Engine), Philip Colligan (Raspberry Pi Foundation), Eric Schmidt

• Concepts: Success disaster, the Osborne effect, 10x engineer, vertical integration, OEM licensing model, Foundation dividend model, Magnificent Seven sectoral distortion, DRAM supply crisis, ROS2 middleware, quantum EDA, AI text watermarking