Senior Finance Associate

Flux is pioneering a new class of AI accelerators called Optical Tensor Processing Units (OTPUs). Our work environment rewards innovation, speed, and bold thinking.

We’re looking for an ambitious Senior Finance Associate to join us at a critical stage of growth. As we enter a stage of scaling rapidly, you’ll play a central role in keeping our financial systems tight, helping us move fast without breaking things. You’ll be hands-on with everything from FP&A to supplier contracts to investor reporting, collaborating closely with Operations, People, and Engineering. This role is based in our Kings Cross, London office and is 5-days a week in the office.

Responsibilities

• Lead budgeting, forecasting, and cash flow modelling.
• Act as a trusted partner to teams across the business, owning purchasing workflows, spend management, and vendor onboarding.
• Prepare high-quality materials for board meetings, investor updates, and financial reporting.
• Support statutory and regulatory compliance in the UK and US, working with external accountants where needed.
• Identify and implement process improvements, automating wherever possible to help us scale.
• Drive cross-functional initiatives that improve financial visibility and operational efficiency (e.g. headcount reporting, capex tracking, cost optimisation).

Skills & Experience

• 3-5 years of experience in a finance, accounting, or FP&A role. Experience in a hardware company and fast-paced environment is a bonus.
• Advanced Excel / Google Sheets skills; confident building, debugging, and owning financial models.
• Experience with Xero and tools like Pleo, Spendesk, Ramp, or similar.
• Highly organised and detail-oriented; you spot errors before others do.
• Proactive, pragmatic, and solutions-focused; you take initiative and make things better.
• Great communicator and confident working with cross-functional teams.

Nice to have:

• Understanding of equity, cap tables, and fundraising processes.

This is a rare opportunity for someone with the right mix of experience, ambition, and appetite for building. But it’s not for everyone. You will thrive here if you:

• See the strategic advantage that working side-by-side in an office can bring. We’re moving quickly, and tight feedback loops matter.
• Are excited to set aside the playbook in favour of systems that actually fit our stage. You’re not afraid to experiment, streamline, and question what’s “standard.”
• Use ChatGPT multiple times a day. Whether it’s drafting investor memos, cleaning up spreadsheets, or pressure-testing a model, you see AI as a force multiplier.
• Champion transparency and believe finance shouldn’t be a black box. You’re excited to help others understand how our business runs and how their decisions impact the health of the business.

Details

• Competitive salary ranging from £75,000 to £95,000, depending on experience.
• Generous stock options in a rapidly growing AI company.
• Based in our new 5,000 sq. ft. office in the AI hub of Kings Cross, London.
• To foster collaboration in our high-growth environment, we require all employees to work from our London HQ and live within a 45-minute commute. We offer an extra £24,000/year incentive for those living within 20 minutes.
• Comprehensive healthcare insurance.
• 25 days PTO policy plus bank holidays.
• Private access to our in-house 3D printer.

If you’re excited to help build the financial backbone of one of the most ambitious hardware startups, we’d love to hear from you. Apply now to join Flux as our Finance Associate and play a pivotal role in accelerating the future of computing.