Chief Growth Officer
Speero
Where to find me
About me
Jonny focuses on experimentation-led growth and has nearly two decades of experience working in experimentation across agency, client, and consultancy roles. He worked at brands such as Boohoo, Sky, and Visa. Most recently, Jonny joined the experimentation agency Speero as Chief Growth Officer.
Q&A
What’s one thing people often get wrong when trying to get different teams to run experiments together?
“They focus on the tool or the tactic of experimentation (e.g., A/B testing software, conversion rate), rather than the overarching strategic objective and the human decision-making process it's meant to inform. This leads to siloed, metric-myopic efforts instead of unified learning towards a common business goal.” Jonny Longden
If a company is just starting to bring all its teams into one shared experimentation approach, what’s the first thing you’d suggest they do?
“The very first step is to design and implement a unified experimentation operating system. This isn't just software; it's a systematized way of working that provides shared frameworks for generating ideas, prioritizing them against strategic goals, managing the workflow of research and validation, and formalizing the human decision-making process based on evidence. It creates the infrastructure for de-risked innovation and continuous learning across all teams.” Jonny Longden
Can you share one experiment you’re really proud of—and what you learned from it?
“One of my earliest experiments, around 2007, was on an automotive website. The site featured a multi-step form for booking a test drive, requiring users to select vehicle specs. I tested a radically simpler version: a basic call-back form asking only for a phone number. This test, which showed the simple form significantly outperformed the complex one, was pivotal for me. It wasn't just about the "win"; it was the moment I realized the power of digital experimentation to challenge assumptions and drive real business impact, directly translating my direct mail testing experience into the digital realm. It marked the definitive start of my career in this field.” Jonny Longden
Who I nominated this year
I nominated Makram Mansour as a Selectee for the Who’s Who in Experimentation 2025.