Back End Engineer - Credit Cards Product Team

iwoca Ltd; City Of London; Hybrid; GBP 70,000 - 90,000; Full time

Job summary

A leading fintech company is seeking a Back End Engineer to design and deliver systems for their new credit card product. The ideal candidate will have experience in creating scalable back end systems, proficiency in Python, and a thorough understanding of relational data models. This hybrid role in London also offers excellent benefits including flexible working, medical insurance, and a culture that prioritizes learning and growth.

Benefits

Flexible working

Medical insurance

Private GP service

25 days holiday plus extra day for birthday

Paid sabbatical after four years

Cycle-to-work scheme

Qualifications

• Experience with microservices or event-driven architectures is a plus.
• Familiarity with financial systems, especially card payment systems is preferred.
• Experience working with data from financial institutions is additional.
• Experience with scalable back end systems for customer-facing products.

Responsibilities

• Design and deliver systems for iwoca’s new credit card product.
• Help shape how services are built and run.
• Create a reliable, scalable, and easy-to-evolve platform.

Skills

Experience designing and operating scalable back end systems

Proficiency in Python

Experience designing relational data models

Experience building and integrating APIs

Pragmatism balancing delivery speed

Experience managing projects end to end

Tools

PostgreSQL

Django

Job description

Back End Engineer - Credit Cards Full Product Team

Hybrid in London / Remote within the 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 team

The Credit Cards team is building iwoca’s newest product for small and medium-sized businesses, giving them a fast, flexible way to manage cash flow alongside our existing loans. We’re aiming to build a market-leading product, as the credit card is a core part of our long-term growth strategy. We’re responsible for the systems, processes, and product features that will make this possible - from platform architecture and credit risk to user experience and servicing.

The role

As a Back End Engineer in the Credit Cards team, you’ll design and deliver the systems that power iwoca’s new credit card product. You’ll help shape how our services are built and run, working with others to create a platform that is reliable, scalable, and easy to evolve. The work will involve iterating quickly, refining solutions, and developing both technical and product skills as the system grows.

The projects

• Data Model and Service Architecture: Shape a Greenfield service architecture outside our existing monolith. Design it to support the scalability, flexibility, and independence from other teams that the product needs.
• Authorisation Service: Design and build the service that responds to authorisation requests when customers attempt to use their card. Ensure it achieves high availability (>99.9% successful response rate), consistently low latency (<0.5s), and capacity to handle 100,000 transactions per day.
• New product features: Build a product customers love, attracting and retaining users. Improve our offer terms, rewards, flexibility, and their control - so their business can thrive from access to instant working capital.

The requirements

Essential:

• Experience designing and operating scalable back end systems for customer-facing products, including high-availability services.
• Proficiency in Python, writing clean, efficient, and well-tested code.
• Experience designing relational data models, ideally using PostgreSQL, with a focus on performance and maintainability.
• Experience building and integrating APIs.
• Pragmatism in balancing delivery speed with managing technical debt.
• Experience managing projects end to end, from understanding business problems to designing and delivering technical solutions.

Bonus:

• Experience with microservices or event-driven architectures, including service-to-service communication and message queues.
• Familiarity with financial systems, especially card payment systems or real-time transaction processing.
• Experience working with data from financial institutions, credit reference agencies, or open banking.
• Experience with Django.

The salary

We expect to pay from £70,000 - £90,000 for this role. But, we’re open-minded, so definitely include your salary goals with your application. We routinely benchmark salaries against market rates, and run quarterly salary and performance reviews.

The culture

At iwoca, we prioritise a culture of learning, growth, and support, and invest in the professional development of our team members. We value diversity in thought and skill, and encourage you to explore new areas of interest to help us improve our products and services.

The offices

• Offices in London, Leeds, Berlin, and Frankfurt with plenty of drinks and snacks.
• Events and clubs, like bingo, comedy nights, yoga classes, football, etc.

The benefits

• Flexible working.
• Medical insurance from Vitality, including discounted gym membership.
• A private GP service (separate from Vitality) for you, your partner, and your dependents.
• 25 days’ holiday, an extra day off for your birthday, the option to buy or sell an additional five days of annual leave, and unlimited unpaid leave.
• A one-month, fully paid sabbatical after four years.
• Instant access to emotional and mental health support.
• 3% Pension contributions and share options.
• Generous parental leave and a nursery tax benefit scheme to help you save money.
• Cycle-to-work scheme and electric car scheme.
• Two company retreats a year, we’ve been to France, Italy, Spain, and further afield.

And to make sure we all keep learning, we offer:

• A learning and development budget for everyone.
• Company-wide talks with internal and external speakers.
• Access to learning platforms like Treehouse.