BSc · CFA · Author
25+ years leading revenue growth, commercial expansion, and operational scale across regulated financial services, fintech, and global alternative investment markets. C-suite mandates at institutions from HSBC to high-growth fintech scaleups. Author, Disruptive Innovation in Financial Services.
25+ articles and insights published from February 2024 to April 2026, across Innovation, Commercial, and Leadership. Available on the Insights page.
The thread running through the career is a rare dual perspective: 25+ years operating on both sides of the vendor relationship in complex regulated financial services environments.
"A commercially astute executive who bridges revenue growth, platform innovation, and operational rigour in regulated environments. Not a conventional C-suite hire. Someone who has operated on both sides of the market."
18 years inside HSBC Alternative Investments on the client side, partnering and building bespoke in-house technology, operations and data models across the alternatives ecosystem, while selecting, contracting, and overseeing the external vendors whose world he later joined. Then crossing to the vendor side at Backstop Solutions and ONYX Capital Group, building commercial operations and monetising proprietary data into external revenue streams. That dual perspective, understanding how institutional clients evaluate, procure, and retain vendors, is what informs the commercial and operational advice One Blackwater brings to regulated firms and their technology partners. Irish citizen, based in London, free to work across the EU.
Which financial services firms will flourish in this age of disruption, and which will be left behind? Drawing on 25+ years of hands-on executive experience, this book delivers battle-tested frameworks for driving commercial growth while maintaining trust and compliance.
From artificial intelligence and Web3 to open banking and quantum computing, the book explores revenue growth, go-to-market strategy, innovation leadership, and regulatory navigation through real case studies including Revolut, BlackRock's Aladdin, and Stripe.
Common Questions
One Blackwater Consultancy Limited advises FCA-regulated financial services firms and their technology partners on revenue growth, commercial operations, and operational scale. The practice is led by Declan Sheehy BSc CFA, with 25+ years of C-suite experience across regulated financial services, fintech, and global alternative investment markets.
Declan Sheehy spent 18 years at HSBC Alternative Investments, scaling the division from $200m to $31.6bn AUM with zero FCA regulatory breaches. He then led EMEA commercial expansion at Backstop Solutions contributing to a 10x revenue acquisition in 2022, served as COO and CTO at ONYX Capital Group (GBP208m derivatives business), and has operated as Chief Revenue Officer at Leo Regtech via One Blackwater Consultancy.
One Blackwater takes on permanent C-suite mandates (COO, Chief Revenue Officer, CCO), fractional and interim C-suite engagements, strategic advisory and board-level roles, and author appearances and keynote speaking on financial services innovation.
Disruptive Innovation in Financial Services (published April 2026, foreword by Graham Rodford, CEO of Archax) delivers battle-tested frameworks for driving commercial growth while maintaining trust and compliance in regulated environments. It covers AI, Web3, open banking, go-to-market strategy, and regulatory navigation, drawing on real case studies including Revolut, BlackRock's Aladdin, and Stripe. ISBN 978-1-919487-10-6.
One Blackwater Consultancy Limited is based in London and operates across the UK, Ireland, Luxembourg, Netherlands, and Portugal. Declan Sheehy holds an Irish passport providing full EU right to work.
Available for strategic advisory, board-level engagements, and executive consulting mandates across regulated financial services, fintech, and regtech.