John has 20 years' experience in leading and training teams of financial modellers in both project and corporate finance, supporting deals and finance for global funds and developers in energy and infrastructure, as well as working capital, valuation and deal models for smaller businesses.

John created the BDO UK modelling methodology, renewed the methodology at Forvis Mazars (building upon the already well-regarded "SMART" methodology), and recently created the methodology for the Lodeum modelling training platform. He specialises in utilising the latest Excel functionality, including dynamic arrays and LAMBDA functions, which are particularly helpful in creating functional models for large global asset portfolio models.

He is a regular contributor to ICAEW Excel thought leadership, such as the 20 principles for good spreadsheet practice and the Excel Spreadsheet Competency Framework.

He is a founder of Lodeum, a global online financial modelling training platform, which will launch in 2026.

Career history

• Member, Financial Modeling Global Leaders Council (opens in new tab)2026 to present
• Member, ICAEW Excel Community committee (opens in new tab)2021 to present
• Chief Innovation Officer, Lodeum2024 to present
• Director, Infrastructure and Energy, Forvis Mazars2017 to 2025
• Associate Director, Corporate Finance, BDO UK2006 to 2017
• Derivatives analyst, Barclays Capital2005 to 2006
• Manager, forensic accounting, Deloitte1999 to 2004

Qualifications

• ACA, Chartered Accountant, ICAEW
• MSc Financial Mathematics, University of Warwick
• MA Mathematics, University of Cambridge

Publications

• Spreadsheet Competency Framework, ICAEW (opens in new tab) (2026)
• The performance of LLMs at modularising financial models, EUSPRIG 2026 (2026)
• Making up with language and models, EUSPRIG 2025 (opens in new tab) (2025)
• 20 principles for good spreadsheet practice, ICAEW (opens in new tab) (2024)
• Forvis Mazars financial modelling methodology (2017 to 2025)
• TRUSt financial modelling standard for BDO (2006 to 2017)

Speaking & training

• Numerous public financial modelling webinars, Forvis Mazars and ICAEW (2017 to present)
• The critical role of communication and standard definitions in financial modelling, Financial Modeler's Corner podcast (opens in new tab) (2026)
• Over a hundred days of financial modelling classroom training delivered at Forvis Mazars