From Financial Chaos to 430% EBITDA Growth

The Situation

OSO are the Kafka experts. Founded in 2018, they help engineering teams across the globe build event-driven applications on Apache Kafka, enabling businesses to access their data in real time and make decisions at the speed their markets demand. Their clients range from fast-growing tech startups to global enterprises, including Lloyds Banking Group, Scania, and Formula 1 racing teams. OSO knows better than most what it means to operate in a high-stakes, high-complexity environment. But for a period, that same complexity had crept into their own back office.

By 2024, OSO was navigating one of the most challenging periods in any business’s life: a founder’s exit. One of the two co-founders stepped away from the business, and with him went oversight of the company’s finances: the accountants had operated under his supervision and the relationship dissolved with his departure. Almost overnight, Sion was left holding not just the full weight of the business, but a financial function with no one at the helm.

At the same time, the business was growing. Sion needed to run the company, lead the team, and serve clients, without the luxury of a co-founder to share the load, and without a finance function he could trust. That’s when Finance Director London stepped in. Not just to fill a gap, but to provide the direction and stability that the business urgently needed.

The Challenge

OSO didn’t need a bookkeeper or an accountant. They needed someone who could do three things simultaneously: resolve the current financial challenges, build scalable processes for the future, and become a trusted advisor as the business made growth decisions in real time.

This is the gap many tech companies fall into during their scaling years: the finance function that worked at £500k simply doesn’t work at £1.5m. Complexity compounds quickly with multi-client billing, deferred revenue, team costs, contractor arrangements, and tax obligations. Without the right financial infrastructure, founders are flying blind precisely when the stakes are highest.

What We Did

Finance Director London embedded into OSO as a fractional finance function, working closely with Sion to provide the much-needed financial direction. The engagement covered:

• A full financial audit to understand the current state of accounts and identify gaps

• Rebuilding the chart of accounts and financial reporting structure to give real-time visibility

• Implementing clear, traceable processes so every number had a source and a meaning

• Acting as a strategic sounding board as OSO navigated growth decisions

• Supporting due diligence for a potential merger, enabling informed, confident evaluation.

The result was a finance function that finally matched the ambition and rigour of the rest of the business.

The Results

Within two years of working together, OSO’s financial trajectory shifted dramatically:

• Revenue grew from £0.9m to £1.7m, a 85% increase

• EBITDA jumped from £99k to £428k, a fourfold improvement

• Leadership gained the financial confidence to make bigger, faster decisions without second-guessing the numbers

But beyond the numbers, the bigger win was clarity. OSO now operates with a finance function that’s genuinely fit for scale, one that supports growth rather than scrambling to catch up with it.

Does this sound familiar?

If you’re running a tech business turning over between £500k and £5m, the chances are you’re managing finances that have outgrown your current setup. The spreadsheets that worked in year one aren’t giving you what you need now. You’re making decisions based on bank balance rather than margin. And your accountant is reactive rather than strategic.

You don’t need to hire a full-time CFO. You need a finance business partner that can give you the clarity and infrastructure to grow with confidence.