Interim Head of Finance | VC-Backed Deep Tech Scale-Up

Harmonic is partnering with a venture-backed deep tech business that pairs proprietary AI software with its own hardware, already in use with UK customers. Having recently closed a significant funding round, the business has grown from 30 to 50 people since July, and is moving from R&D into production ahead of large contracts. It needs its finance function built for the company it is about to become, not the one it is today.

Reporting into the Chief of Staff and working closely with the COO and founder-CEO, this six-month interim will own day-to-day finance and set up the controls, processes and reporting the business needs to scale. It is hands‑on, but it is equally about people: most of the business are engineers, and the right person will spend as much time explaining the numbers and getting the right information from manufacturing, procurement and marketing as working in the ledger.

You will also coach a part-qualified accounts assistant.

• Review and correct coding across the ledger, and put inventory, cost of sales and fixed asset accounting on a proper footing.
• Deliver the December year-end and audit preparation.
• Build a longer‑range cash flow forecast that reflects long supplier lead times and committed parts orders.
• Produce management accounts and board reporting that a non‑financial founder can act on.
• Partner with engineering, manufacturing, procurement and marketing to build budgets, explaining the why behind what finance needs.
• Set up purchase‑to‑pay, expenses and supplier processes that will scale to 50+ people and future overseas entities.
• Coach and develop the accounts assistant.
• Support R&D tax credits, lease accounting and invoicing for larger contracts.
• Qualified accountant (ACA / CIMA / ACCA).
• Senior, hands‑on finance experience (Financial Controller, Head of Finance or FD) in a start‑up or scaling business.
• Exposure to hardware, manufacturing or physical product accounting: inventory, cost of sales and fixed assets.
• A natural communicator who can explain finance clearly to engineers and non‑financial leaders.
• Adaptable: tailors the approach to the business rather than applying a template, and is comfortable working from incomplete information.
• Able to be on site at least three days a week.
• Experience across more than one industry.
• R&D tax credit claims and Sage 50.
• Preparing a finance function for international expansion or group reporting.