Meet Gus Bartholomew, Co-Founder at Sustainability Consultant Marketplace: Leafr

Tell us about Leafr

Leafr is a marketplace of independent sustainability consultants. We connect companies with the right experts exactly when they need them. The old model of hiring big teams or consultancy firms doesn’t fit how businesses want to work today. It’s too slow, too expensive, too generic. We’re building something leaner, more flexible, and more human: a platform that makes finding sustainability and CSR expertise as easy as booking a meeting.

How did you come up with the idea for the company?

My co-founder Nick had the idea. He’d been on both sides of the table, working inside a big consultancy firm and later as an independent contractor. He saw first-hand that companies struggled to get the right expertise quickly, while highly capable independent sustainability experts lacked visibility and access to the right projects.

I have to admit that a few years back, when running my previous business, I was sceptical about the fractional talent model. It sounded like a buzzword. That changed when I hired a fractional expert for a fast-moving project. It turned out to be one of the best decisions I’ve made. The speed, the impact, the value compared to the slow process of hiring or the costly approach of bringing in agencies.

This model, when done right, is unmatched in value. It gives companies immediate access to seasoned expertise and gives experts the freedom to work on projects where they can deliver real impact. Leafr is the infrastructure that makes that model accessible, scalable, and trusted.

Tell us about your core product or service

At its core, Leafr is a two-sided marketplace. For businesses, the value is simple: access to trusted sustainability and ESG experts who have actually been there and done it. Not theorists, not armies of juniors, but people who know how to deliver because they’ve done it before. They can be scoped, priced, and onboarded quickly, without the drag of typical hiring. On the other side, expert CSR and ethical business consultants get a steady flow of relevant projects and the infrastructure to manage and grow their practice.

We focus on removing friction from both sides. Our consultant pool spends less time chasing work and more time doing it. Companies stop wasting months searching and start executing.

What most excites you about the sustainability industry?

What excites me is that sustainability has finally moved from the margins to the core of business strategy. Regulation, supply chain risk, and customer expectations are forcing companies to treat sustainability like any other mission-critical function.

That shift is creating a new type of professional culture. It’s not about writing a CSR report anymore or aligning with UK supply chain regulations. It’s about redesigning products, restructuring supply chains, embedding circularity, and hitting hard targets under real scrutiny. That requires a different type of talent.

Leafr helps companies tap into that execution mindset without the drag of bureaucracy. We’re seeing sustainability teams that are lean, sharp, and impact-focused — plugging in specialists on-demand, scaling expertise as projects demand. That agility excites me, because it’s what delivers results and enables companies to execute initiatives in a cost-effective, impactful way.

What has been the biggest challenge you’ve had to overcome along the way?

Building our network. Leafr works because of the quality of the consultants on the platform. Getting the first hundred world-class CSR experts took time, trust, and a lot of conversations. Now it’s snowballing. Experts want to be where the work is, and companies want to be where the experts are. But that early grind was tough. The classic cold-start problem of a marketplace.

What is your number one piece of advice to aspiring entrepreneurs?

Hofstadter’s Law: “It always takes longer than you expect, even when you take into account Hofstadter’s Law.”

What can we hope to see from Leafr in the future?

More tools for both sides of the marketplace. For companies, we’re developing discovery tools to match them with the right expertise faster and at lower cost. We have just launched a Sustainability Project Brief Generator which helps teams turn rough project ideas into a clear, consultant-ready brief in 30 seconds.

For consultants, we’re building ways to streamline everything from proposals to invoicing, to communicating what they do. Our new “Sustainababble Translator” helps experts turn complex acronyms and terms into tangible, actionable ideas.

Our goal is simple: make it easier, faster, and better for companies to access the sustainability skills they so desperately need, so more companies can actually deliver on their goals.