Interim Financial Controller | AI Deep Tech Scale-Up

Interim Financial Controller | AI Deep Tech Scale-Up | London/Hybrid

Harmonic are delighted to be partnering exclusively with one of the UK's most exciting start-ups operating cutting-edge AI scale-up in their search for an Interim Financial Controller.

Backed by top-tier global investors and experiencing rapid international growth following one of the largest fundraises in Europe in 2025, the organisation is scaling quickly across multiple regions. This role will suit someone who thrives in an agile, innovative environment and enjoys building structure, technical discipline, and high-performing teams within a scaling finance function.

The Role

Reporting directly into the CFO, this is a pivotal leadership position overseeing the group's financial operations, technical accounting, and reporting frameworks. You will take ownership of multi-entity consolidation, compliance, controls, and financial governance.

The role combines hands-on technical depth with strategic oversight, partnering closely with senior leadership as the business continues its fast-paced global expansion.

Key Responsibilities

• Deliver accurate, timely, and comprehensive financial reporting, providing clear insights and commentary to senior stakeholders.
• Manage the full external audit process, acting as the primary point of contact and presenting outcomes to the Audit Committee and Board.
• Oversee the consolidation of multi-entity, multi-territory financial results, ensuring consistency, accuracy, and alignment with accounting standards.
• Lead cash management activities, including cash flow forecasting, FX exposure monitoring, and continuous improvement of treasury processes.
• Drive efficiency and consistency across AP, AR, payroll, and cash operations, working with teams across different geographies.
• Oversee compliance across all legal entities and business units, ensuring alignment with relevant accounting, tax, and regulatory requirements.
• Own the organisation's key accounting policies, including areas such as transfer pricing, capitalisation policies, and complex technical judgements.
• Define and track clear finance KPIs, ensuring alignment with business priorities and strategic goals.
• Take responsibility for the financial systems and tech stack, including the ERP and integrations with wider business tools.
• Partner cross-functionally to enhance financial literacy, operational alignment, and decision-making across the organisation.

What We Need to See (Essential)

• Fully qualified accountant (ACA/ACCA or equivalent).
• Excellent understanding of IFRS and strong technical accounting capability.
• Experience in a tech based venture capital backed business.
• Proficiency with Xero

Day Rate: £500–£550 per day (Outside IR35)

Contract Length: 6 months

Start Date: ASAP

Location: London/Hybrid (3 days in the office)

If you are interested – to be considered for the role please forward your CV to ed.naish@harmonicfinance.com

At Harmonic, we are dedicated to fostering an inclusive and equitable workplace. We actively welcome applications from individuals of all backgrounds and assure you that every candidate will be thoughtfully considered for the roles we represent, without regard to race, religion, gender expression, disability, or sexual orientation.