Over the summer, we’ll be introducing the individuals who make Calderon Search & Advisory what it is, sharing their career stories, passions, and the work they’re doing to support our clients and their leadership goals. We’re starting this week with our Managing Director, Harco J. Leertouwer whose leadership, values, and wealth of experience shape the foundation of our work.
Harco, your journey into Sustainability Leadership Search & Advisory stems from deep personal roots and a sharp professional pivot. Can you share how your early life and career progression shaped your commitment to founding Calderon Search & Advisory?
HJL: Absolutely. My passion for nature began at the age of 8, I was editor-in-chief of a magazine called “Naturepeace” – we had 6 subscribers: our parents, the neighbours and the local hockey team’s coach. I was brought up in a “heel groen gezin”, a very green family – my mother instilled eco-conscious habits early on, even making me, at the age of eight, repay her for plastic grocery bags if I brought them from the supermarket to bring home groceries, instead of using the cotton shopping bags we had at home. That upbringing planted the seed. Fast forward, in 2012 our first daughter was born 8 weeks early, threatening both her and her mother’s life and a few months later, my best friend died in his early forties of cancer. Seeing life and death so close, I realised time is fleeting, and I decided I wanted to dedicate my work to protecting what really matters. Professionally, I built two decades of executive search experience in different countries in Europe, before taking up the role of MD for Europe in 2020 for a niche player in sustainability. In June 2025 I founded Calderon Search & Advisory, to help shape leadership that doesn’t just meet today’s demands – but steers organisations toward a more resilient, responsible and regenerative future.
How do you translate your sustainability values in your personal day-to-day life, outside your work?
HJL: In 2016, I transitioned from a vegetarian to a fully plant-based diet. For almost two years now, I’ve been living without a car, giving up even an electric vehicle. Driving in a city like Amsterdam felt unnecessary and counter to my values, especially since I can meet 95% of my transportation needs by walking, cycling, or using public transport. I avoid flying whenever possible, try to buy second-hand instead of new, and support a political party with the most ambitious climate agenda. One area where I’m still trying to improve is reducing single-use packaging. Whilst I never travel without my reusable water bottle and coffee cup, I still find myself using more packaging than I’d like.
What does “impact” mean to you personally?
HJL: Impact, to me, is about shifting systems. Whist I’ve never been interested in the purist route and where I think sustainability shouldn’t feel like a punishment, or a lifestyle choice available only to the privileged few, I’m not interested in incrementalism dressed up as progress. Real impact happens when a leader redefines what’s possible not just for their company, but for their industry. Personally, I feel impact when I help someone step into a role where they can do exactly that. When I see a candidate we placed rewriting a company’s playbook on climate, or redefining equity in the supply chain — that’s when I know we’re doing meaningful work.
What’s one opinion you have about sustainability leadership that might be controversial?
HJL: I think we often overestimate what sustainability leadership can achieve in isolation. That might sound controversial, but hear me out: we tend to treat sustainability like a department rather than a strategic lens that should inform every decision, from finance to procurement to product development. The controversy is this: real sustainability leadership shouldn’t sit on the sidelines, it should be embedded into the CEO’s agenda, the CFO’s planning, even the innovation pipeline. When it’s siloed, no matter how brilliant the individual is, their influence is limited. True transformation happens when sustainability stops being a function and becomes a mindset across the whole C-suite.
Have you ever seen a company ignore your advice and regret it later?
HJL: Yes, and it’s never a moment of “I told you so”, it’s more disappointment than anything else. A few years ago, I advised a client to take a bold step in hiring a sustainability leader from outside their industry. They were fixated on sector experience and ended up choosing someone very traditional. Within a year, the person left, the culture hadn’t moved an inch, and they lost critical time. What they needed was someone to challenge the status quo, not just blend in. It taught me that some companies don’t just need advice, they need the courage to act on it.
What’s the hardest business decision you have taken in the past year?
HJL: Walking away from a successful partnership that no longer aligned with my values. It’s easy to stay in a system that works on paper. But I couldn’t keep doing work that felt like ticking boxes. Starting Calderon Search & Advisory was a leap into the unknown, but also a declaration: we only work with people serious about systemic change. That clarity came at a cost, but I’d do it again in a heartbeat. The hardest decisions are often the ones that bring you back to your purpose.
And finally, where would you like Calderon Search & Advisory to be one year from now?
HJL: In 12 months from now, I’d like Calderon to be known not just as an executive search firm, but as a trusted advisor to organisations that are serious about systemic transformation. We want to be the go-to partner for companies looking to move beyond box-ticking and genuinely integrate sustainability and equity into their leadership DNA. Practically, that means deepening our advisory work, helping boards and CEOs think more holistically about what kind of leaders they need, not just to meet KPIs, but to stay relevant in a rapidly shifting world. It also means growing our global network of diverse, bold leaders who are ready to challenge the norm.
And on a personal level? I want us to stay uncomfortable – in the best way. If we’re not pushing ourselves or our clients to think differently, we’re not doing our job.
For more info, visit www.calderon-sa.com or send a message to info@calderon-sa.com
On October 18th, 2025, Harco be at the start of the The IRONMAN Group #Ironman #Cascais 70.3 taking on this challenge and he will raise €6,000 for Stichting Kinderen Kankervrij (KiKa), a foundation dedicated to funding vital research for childhood cancer such as at the Prinses Máxima Centrum voor kinderoncologie . You can still support and every amount, no matter how small, helps: https://supporta.com/9ak2/0ork7hcs2x Many thanks in advance!!!
