Leadership

Julian Randles

Julian Randles

CFO

Joined CZ: 2012

After gaining a mathematics degree and qualifying as an accountant with Grant Thornton, Julian has built up global experience in the commodities trading industry through roles at ED&F, Olam, and now Czarnikow. An in-depth knowledge of the commodities industry and international commerce enables Julian to manage and oversee Czarnikow’s diverse operations from a position of strength.

Tiago Medeiros

Tiago Medeiros

Managing Director, Americas

Joined CZ: 1998

Tiago Medeiros joined Czarnikow in 1998 at Czarnikow Brasil Ltda. and currently leads the Group’s operations across the Americas. Under his leadership, Czarnikow has built a strong and diversified presence in the region, operating across bulk agricultural commodities, ingredients, and energy. He played a pivotal role in establishing the Corporate Finance and Structured Finance divisions.

William Rook

William Rook

CEO

Joined CZ: 1989

With over thirty years of in-house experience, William has gained robust global knowledge of the industry and a reputation for strategic innovation, particularly in the white sugar business. Through the development of our service-driven trading model, he has launched our market-leading containerised white sugar business, expanded our refined sugar trading in Africa and the Middle East, and initiated our Sustainability programme, Vive.

Adam Leetham

Adam Leetham

Chief Risk Officer

Joined CZ: 1995

Adam joined Czarnikow in December 1995 and has over 30 years of service with the company. During this time, he has held senior leadership roles across Czarnikow’s global network, having been based in Moscow, Singapore, New Delhi, São Paulo and London. After leading the Agriproducts business for 14 years, he now serves as Czarnikow’s first Chief Risk Officer, reflecting the company’s growing focus on enterprise-wide risk management.

Nicholas Wainwright

Nicholas Wainwright

Managing Director, Asia & EMEA

Joined CZ: 2000

Nicholas joined Czarnikow in 2000 immediately after graduating with a degree in English Literature from the University of Edinburgh and is a member of the Executive Committee and the Risk Committee. He began his career on the London brokerage desk before joining William Rook’s Africa and Middle East team in 2002, where he managed industrial customer relationships across the region, with a particular focus on Coca-Cola. 

Steve Lazenby

Steve Lazenby

Chief People Officer

Joined CZ: 2025

Steve Lazenby joined the Group in January 2025 and is a member of the Executive Committee. He is a Fellow of the Chartered Institute of Personnel and Development and brings more than twenty years of HR leadership experience across a wide range of sectors. In his current role, Steve works closely with the executive leadership team to build a performance-led culture and leads the Human Resources function in partnering with the business to deliver the Group’s ambitious growth strategy.