Unity Advisory appoints Marc Lien as Chief AI Officer

Unity Advisory has appointed Marc Lien as chief AI officer as the firm reaches 100 employees.

Lien will also join the board and founding leadership team. He will work with chief executive Marissa Thomas, chair Steve Varley and the wider leadership group on the technology and delivery set-up behind the firm's AI-focused advisory model for chief financial officers.

The appointment brings a senior financial services and consulting executive to a young advisory firm building its offering around artificial intelligence. The hire coincides with the headcount milestone, signalling growth in a market where finance leaders are under pressure to improve efficiency, reporting and deal execution.

Lien was most recently a senior advisor at Warburg Pincus, where he advised deal teams and portfolio companies on AI-led value creation. Before that, he spent 11 years at Lloyds Banking Group, where he led the UK's largest credit-card franchise and served as chief executive of MBNA.

Earlier in his career, he spent 12 years at McKinsey & Company and holds an MBA from Harvard Business School.

Unity Advisory describes itself as a CFO advisory firm focused on mid-market organisations. It combines finance, tax and deals work in a single model and operates without an audit practice, which it says removes conflicts that can affect larger professional services firms.

The company is backed by Warburg Pincus, where Lien most recently held an advisory role. That connection gives the appointment added significance, linking the firm's investor base with an executive brought in to shape how AI is used across the business.

Thomas linked the appointment to the company's growth. "It's a pleasure to welcome Marc at such an important moment for the business. He brings experience that aligns closely with how we are building, combining strong advisory thinking with the ability to deliver and scale practical solutions," she said.

She also highlighted the workforce expansion. "We're also reaching an important milestone as we welcome our 100th colleague. In a short space of time, we've built a high-quality team and strong momentum, driven by the work underway and the demand we're seeing from clients," Thomas said.

Career background

Lien's background spans consulting, banking and private equity, areas that increasingly overlap as firms assess how AI could reshape operations and advisory work. His experience in consumer finance at Lloyds and MBNA may also be relevant for a business advising finance chiefs balancing investment demands with pressure on costs and controls.

Professional services firms have been racing to define AI strategies, but approaches vary widely. Some have focused on internal tools to improve staff productivity, while others are trying to redesign client work and delivery processes around automation and data models.

Unity Advisory is positioning itself in the latter camp. In comments released alongside the appointment, Lien drew a distinction between adding AI tools to established workflows and building an advisory firm around the technology from the outset.

"Most AI in professional services today is cosmetic, with a model dropped on top of the old way of working. Unity has been designed so AI is the runtime of the firm, not a layer bolted on. Across banking, consulting, and PE, it's the first firm I've seen designing the right way from the ground up," Lien said.

The hire suggests Unity Advisory wants AI leadership represented at the top of the organisation rather than treated as a support function. By placing Lien on the board and in the founding leadership team, the firm is tying technology design directly to its operating model and client delivery.

That approach stands out in a sector where many firms still place AI responsibility within innovation teams or technology departments. At Unity Advisory, the role appears embedded in the core management structure as the company expands its workforce and builds out its offer to the Office of the CFO.

Lien will help shape the technology and delivery architecture behind that model. As he put it, the firm was "designed so AI is the runtime of the firm, not a layer bolted on".