Fractional Financial Controller | High-Growth AI Start-Up | 2 days per week

The Client

Harmonic are delighted to be working with a high-growth, venture-backed technology business to find them a Fractional Financial Controller to support over a 6-month engagement (2 days per week).

The business operates at the cutting edge of its field, partnering with enterprise and international clients, and is experiencing rapid growth. Despite this, they maintain a lean, collaborative, and fast-paced environment typical of an early-stage scale-up.

They are now looking for an experienced finance professional to bring structure, oversight, and commercial insight to their finance operations during a key phase of growth.

The Role

This is a hands-on and varied role, requiring a detail-oriented and proactive individual who can take ownership of the finance function while partnering closely with senior stakeholders.

You will be responsible for ensuring the smooth running of day-to-day finance operations, improving processes, and providing clear financial insight to support decision-making.

This role would suit someone comfortable operating in a scaling business where processes are still evolving, and who can balance both operational delivery and strategic input.

Responsibilities

• Oversee and manage the outsourced accounting function
• Ensure accurate and timely financial reporting, including monthly management accounts and board packs
• Monitor budget vs. actuals, providing variance analysis and commentary
• Support cashflow forecasting and ongoing tracking of financial performance
• Maintain robust financial controls and ensure compliance with statutory requirements
• Partner with senior stakeholders to support financial planning and scenario analysis
• Provide insight into business performance, highlighting risks and opportunities
• Support preparation of materials for investors and board reporting
• Oversee invoicing processes to ensure accuracy and alignment with contractual terms
• Oversee payroll coordination with external providers
• Ensure accurate record-keeping across financial and operational documentation
• Support equity and cap table administration where required
• Liaise with external advisors (accountants, legal, payroll) to ensure compliance
• Assist with entity management and international expansion requirements where relevant

Essential Experience

• Fully qualified accountant (ACA, ACCA, or CIMA)
• Previous experience in a Financial Controller or similar role within a growing business
• Strong technical grounding with the ability to oversee end-to-end finance operations
• Experience working with outsourced finance providers
• Comfortable working in a fast-paced, scaling environment

Bonus Experience

• Prior experience in a technology or SaaS business
• Exposure to investor reporting and fundraising environments
• Experience with subscription-based or contract-based revenue models
• Familiarity with equity or options administration

Day Rate: £450-£550 per day (Outside IR35)

Location: Remote, with occasional travel to London HQ.

Start Date: ASAP

Contract Length: 6 months (2 days per week)

Please feel free to get in touch with Ewan Fenley for more information ()

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.