I had the pleasure of working with the Jonathan and the WE Sustainability Consulting team while I was Head of Group Sustainability at Old Mutual. They bring broad expertise across the sustainability domain, but what differentiates them is their deep capability in ESG data management. They are able to define and structure ESG data, implement effective collection and management processes, and transform the data into reliable insights that strengthen reporting, support better business decisions, and help organisations improve their ESG ratings. Throughout our engagement, Jonathan and team consistently demonstrated technical excellence, strategic thinking, and a strong focus on delivery. Jonathan easily builds credibility with stakeholders, navigated complex challenges, and delivered high-quality outcomes. I would highly recommend Jonathan and his team to any organisation looking for a trusted sustainability partner with deep data expertise.
Shakira NursooEnterprise Strategy & Sustainability Executive | Old Mutual · Kearney | London Business School · UCT GSB | MBA · PMP · PrEng
Working with Jonathan has been an absolute pleasure. He’s an incredibly passionate sustainability practitioner. He is solutions driven and brings a wealth of data and systems thinking to every project he’s involved in. Over and above his passion and dedication to work, I appreciate Jon’s passion for people and how he aims to empower and upskill those around him at every turn. Working with him and leveraging his understanding of sustainability reporting frameworks, data management and ratings agencies made it easy for me to effectively do my job in reporting for the organisation. He always availed himself and is a super collaborative team member who ensures all inputs are taken into account, while providing strategic guidance on projects.
Lerato SabasabaSustainability Risk Management and Reporting Manager at Land and Agricultural Development Bank of South Africa
I am pleased to recommend Jonathan Weimers, whom I worked with directly during my time as Head of Sustainability at Old Mutual Group. Jonathan consistently provided excellent service, he was reliable, responsive, and committed to completing allocated work to a high standard and assisted others in ensuring the team delivered. He was always available when needed and demonstrated a strong understanding of sustainability data and the requirements of rating agencies. Based on my experience working with Jonathan, I would confidently recommend him for opportunities requiring expertise in sustainability reporting, data, and ratings.
Portia BangerezakoConsultant Karmino Impact | Former Head of Sustainability at Old Mutual
