Full Stack Finance Builder in London

Can you help us fix the world's most broken supply chain? The fashion industry produces over 100 billion garments a year. 60% end up in landfill, not because people don't want these clothes, but because the supply chain for getting secondhand fashion from donation to resale is completely offline, manual, and broken. Fleek is fixing this. Our mission is to make secondhand the first choice. We're building the infrastructure powering the global secondhand clothing trade, through a B2B marketplace and the AI systems digitising the supply chain behind it.

Through Fleek, vintage stores, online resellers, and retail buyers source graded secondhand inventory directly from wholesalers and rag houses across multiple countries. Our key enabler is FleekSort, an AI model fine-tuned on secondhand fashion, that can grade, price, and categorise items with just a photo, turning what has historically been an opaque and manual trade into a structured, searchable, and tradable global inventory layer. Since 2022, we've saved 9 million items from landfill and tripled in size year-on-year. We've raised ~$50M from a16z, Y Combinator, HV Capital, and others, and have recently closed our Series B. Our advisors and private investors include operators behind Depop, Shopify, and Postmates. Today, we serve thousands of resellers and retailers across the UK, Europe, and the US. With the secondhand fashion market projected to reach $350B by 2027, Fleek is building the AI-native operational and financial backbone for secondhand commerce globally.

We're looking for people who want to build something that matters, and move fast doing it. Sound good? Keep reading.

About the Role: We’re hiring a Full Stack Finance Builder to sit at the intersection of finance, product and engineering. This person will help Fleek automate finance workflows and accounting logic by turning business events into clean system behaviour, integrations and ledger outputs. It’s an unusually cross-functional role for someone who likes building real systems, not just analysing them.

Why This Role Stands Out: This is not a standard finance systems role, and it’s not a standard software role either. The challenge is to understand how Fleek’s business actually works, how order states change, how cash moves, how capital gets allocated and then encode that into finance automation. That means building the connective tissue between the product, the data and the accounting layer.

What makes the role special is the blend. You need enough technical ability to build, enough product sense to understand what should happen and enough finance context to map business events into accounting outcomes. If you enjoy operating across domains and solving messy operational problems with systems, this is a rare opportunity to do it with real ownership.

What Makes You a Fleek Full Stack Finance Builder?

• Technical First: You’re a builder at heart. You’re comfortable shipping integrations, stitching systems together and using code or automation to remove manual finance work.
• Product-Minded: You don’t just build what’s asked. You want to understand the business event, the user flow and the operational edge cases before deciding what the right solution is.
• Finance-Literate: You don’t need to be a career accountant, but concepts like ledgers, chart of accounts and accounting entries are familiar enough that you can build with confidence.
• Data-Driven: You like working from underlying system logic and operational events not hand-wavy process maps.
• Cross-Functional by Default: You enjoy working across finance, product and engineering and you’re energised by roles that don’t fit neatly into one box.

What You'll Do:

• Automate Financial Reporting: Build systems that translate business events into financial reporting.
• Build Integrations: Connect Fleek’s internal systems and databases with tools to reduce manual workflows and improve finance accuracy.
• Map Business Events to Ledger Outcomes: Help define which events in the business should trigger which accounting entries and make that logic operational.
• Work Across Functions: Partner with finance, product and technical stakeholders to understand the current state and build better system behaviour.
• Improve the Finance Stack: Reduce dependence on manual workarounds by creating scalable finance infrastructure that grows with the business.

What You Bring:

• Strong technical building ability; this is the top priority for the role.
• Product and data acumen; the ability to understand what should be built, not just how to build it.
• Enough finance knowledge to understand ledgers, chart of accounts and accounting entries.
• Experience building integrations, internal tools, automations or systems that connect operational workflows to finance or data outputs.
• Comfort working across multiple teams and disciplines.
• Experience in fintech, finance tooling or operational systems is a plus.
• Experience deploying AI agents or similar automation tooling is a plus.
• A background that blends finance with product or technical work is especially attractive.
• A genuine excitement for solving messy business problems with systems, automation and first-principles thinking.

Ready to build the infrastructure for the world's fastest-growing fashion economy? If you want to work on genuinely hard problems, with a world-class team, at a company that's tripling annually, we'd love to hear from you.

The Practicalities:

• Location: London HQ, E1, Spitalfields / Shoreditch.
• Work model: In Person, with trust based flexibility.
• Stage: Post-Series B, hyper-growth.
• Team: 100+ across London, India, and Pakistan.
• Culture: High ownership, non-hierarchical, fast-moving. Founder-led with strong opinions loosely held.

What's In It for You? Fleek is building the technology infrastructure for a $350 billion market that has never been digitised. Joining now means you'll be part of the team that defines how the secondhand economy works, at scale, globally.

Why people join Fleek:

• The problem is real: 9 million items saved from landfill since 2022. 17,400 tonnes of CO₂ avoided. Your work has tangible, measurable impact.
• The AI is genuinely novel: FleekSort is the world's first LLM fine-tuned on secondhand fashion. This isn't a GPT wrapper, it's a proprietary model solving classification problems that don't exist anywhere else.
• The growth is exceptional: tripling annually, backed by a16z, Y Combinator, HV Capital and others.
• The timing is perfect: EU regulation is mandating the infrastructure Fleek builds. The secondhand market is growing 3x faster than new fashion. You're catching a wave.
• You'll have real ownership: 100-person company, no bureaucracy. You'll shape decisions and see the impact of your work immediately.

Benefits:

• Equity / share options.
• Pension.
• Private health benefits.
• Learning and development budget.
• Team socials and offsites.

Our Values: Five values shape how we work at Fleek:

• Dream Big and Disrupt Yourself: Push the most ambitious version of what you're building. Step out of your comfort zone. Nothing is out of reach.
• Absolute Ownership: The buck stops with you. Drive initiatives to completion. Experiment, learn, persevere. The job isn't done until the job is done.
• Curiosity Leads the Way: Don't accept anything at face value. Ask questions you don't know the answer to. That's how you innovate.
• Talk to the Customer: Deeply understand their challenges, motivations, and ambitions. Every decision starts with the customer at the centre.
• Embrace Diversity: A global team building for a global supply chain. Bring your authentic self and embrace the diversity of everyone you encounter.