Solution Architect - Payments
3-month contract (Outside IR35)
London, UK
The company
Imagine a world where every small business has the power to thrive. That's the world we're building at iwoca. Small businesses aren't just statistics – they're the heartbeat of our communities, the character of our high streets, and the engine of our economy. Since 2012, we've revolutionised how these businesses access finance, turning what was once a lengthy, frustrating process into something remarkable: funding that's fast, flexible, and actually works for modern businesses.
Our impact speaks for itself: we've provided billions in funding to over 150,000 businesses across Europe, making us one of the continent's leading fintech innovators. But we're just getting started. Our mission? To empower one million businesses with the financial tools they deserve.
We combine cutting-edge technology and data science with genuine human understanding to make finance feel less like a barrier and more like a superpower. Whether it's managing cash flow or seizing unexpected opportunities, we ensure businesses get the funds they need – often within minutes.
The role
The objective of this 3-month contract is to deliver a complete set of detailed technical product requirements for iwoca’s payments system and credit card ledger, laying the foundation for a robust and scalable product. You will play a key role in building cross-functional clarity by leading focused walkthroughs and producing a practical Q&A reference to support implementation, testing, and onboarding. Success will be measured by the timely delivery of clear, actionable documentation and a step-change in team understanding of the payment infrastructure and ledger requirements.
You will:
Deliver a complete set of technical product requirements for iwoca’s payment processing infrastructure and credit card ledger
Define how all transaction types (e.g. authorisation, clearing & settlement, repayments, chargebacks, interest, cashback) affect balances, limits, fees, and system state.
Define technical requirements to support the authorisation flow, payments infrastructure and the credit card ledger.
Ensure alignment with Visa/Mastercard scheme rules, regulatory requirements, and internal accounting principles.
Educate the team on credit card ledger requirements and processing flows
Run structured walkthrough sessions with Product, Engineering, and Finance to explain the transaction logic, authorisation flows and scheme nuances.
Support knowledge sharing by answering queries and aligning cross-functional understanding.
Support the architectural design of the payments and credit card ledger system, actively contributing into it.
Create a Q&A reference document
Compile a structured, living document addressing key questions raised during the project, covering edge cases, ledger behaviours, scheme rules, and design decisions.
Ensure it serves as a reference for engineers, QA testers, auditors, and future team members.
The requirements
Essential:
Experience working with card payments, issuing or processing platforms, tokenisation, and card scheme rules.
Expertise in payment protocols and security standards such as EMV, PCI, and scheme-specific APIs.
Direct involvement in modelling end-to-end card transaction flows: authorisation, clearing, settlement, chargebacks, and reconciliation.
Ability to convert business rules and scheme regulations into system behaviours and requirements.
Experience working alongside cross-functional teams including Product, Engineering, Compliance and Finance, with enough technical understanding to contribute meaningfully.
Comfortable writing precise, testable requirements and reviewing their implementation with engineers.
Able to communicate clearly with both technical and non-technical teams, and document decisions for traceability.
Bonus:
Awareness of ISO 20022 messaging and PSD3 impacts.
