04 / Studio

Studio.

One founder, a small set of trusted collaborators, and a preference for doing fewer things properly.

Y.F. Zhang
London · 02:05

I have spent fifteen years building software and founded three companies. The first was Tenmaker, in 2013. Today I am the founder and CEO of COSX, the agent operating system for regulated industries.

Before COSX, I was CTO of Bite Investments for six years: an FCA-regulated fintech for alternative investments. I led the team that built Bite Stream, took the company to SOC 2 Type 2, and won industry awards along the way, including Best Fundraising Solution at the Private Equity Wire US Emerging Manager Awards 2023.

That work taught me to design compliance, audit trails and security in from the start. My technical work today is cloud-native architecture on Cloudflare, Azure and Kubernetes, and AI agents for regulated work. I studied computer science in Nanjing and at Northumbria University, and I am based in London.

{PORTRAIT}
FIG. 01Y.F. Zhang
01 / Timeline

Founded and built, in order.

2013 — 2019 Tenmaker
2019 — 2025 Bite Investments
2026 — NOW COSX
2026 — NOW Y.F. Zhang & Co.
02 / What I do

Three ways to work with us, each priced before we start

Fixed prices, excluding VAT. 30% to start, the rest when you accept the work. Or £200 an hour. Two ways to pay
Brand. Names, identities and the rules that keep them consistent. Naming and name checksWordmark, icon, type and colourStationery, social and launch piecesGuidelines your team can use From £9,0004–8 weeks
Product. Apps, SaaS and internal tools, designed and built by the same person. Research with real usersInterface and interaction designiOS, Android and web buildsThirty days of fixes after launch From £30,0008–16 weeks
Architecture. Systems for regulated work that can show their workings to an auditor. A review of what you run todaySecurity and data protection by designAudit-ready documentation for SOC 2 and the FCACloud set-up on Cloudflare, Azure or Kubernetes From £6,0001–3 weeks
03 / How we work
01 Brief. You tell us what you are making. A few lines is enough. We reply within two working days.
02 Estimate. A written estimate in hours, and one fixed price for the result.
03 Fixed stages. The work runs in fixed stages, each reviewed with the person doing it.
04 Handover. You accept the work, then the balance is due. The files and documentation are yours.
04 / Rates

Two ways to pay.

Pay for the hours, or pay for the result. Most work suits the second.
By the hour £200 an hour£1,500 a day
  • ·A written estimate before we start
  • ·Invoiced every two weeks, with a log of the work
  • ·Stop at any time. You pay for the hours used.
Suits advice, architecture reviews and work inside an existing team. Book time
By the result Recommended One fixed priceAgreed before we start
  • ·We write down together what “done” means
  • ·30% to start. The rest only when you accept the work.
  • ·If it falls short of what we agreed, we keep working at no extra cost. If we still cannot get there, you do not pay the balance.
Suits brands, websites and apps: anything with a clear finish. Ask for a price ✓ Accepted

We offer the second because we would rather be measured on the work than on the clock.

Prices exclude VAT where it applies.
Contact

Ready when you are.