Staff Back End Engineer - Credit Cards Full Product Team

iwoca Ltd; City Of London; Hybrid; GBP 100,000 - 140,000; Full time

Job summary

A leading fintech company in London is looking for a Staff Back End Engineer to develop their new payments platform. This role involves overseeing the platform's architecture, resolving complex engineering challenges, and mentoring a team of engineers. Candidates should have experience in designing high-availability payment systems, proficiency in Python, and a strong background in payments API integration. The position offers a salary range of £100,000 to £140,000 with a focus on flexibility and professional development.

Benefits

Flexible working

Medical insurance

Private GP service

25 days' holiday plus additional leave options

Paid sabbatical after four years

Cycle-to-work scheme

Learning and development budget

Qualifications

• Experience designing and operating payments systems with 10,000+ transactions per day.
• Proficiency in Python and experience with PostgreSQL.
• Experience in mentoring and setting technical standards.

Responsibilities

• Build a new payments platform managing its lifecycle.
• Own architecture and solve complex problems.
• Influence team growth while delivering customer-focused features.

Skills

Designing highly available payments systems

Object-oriented programming (Python)

Data model design for payments systems

API and distributed systems integration

Mentoring engineers

Clear communication

Education

Degree in maths, physics, computer science, or related field

Tools

PostgreSQL

Django

Job description

Staff 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

This is an opportunity to build a critical, new payments platform. As a Staff Back-end Engineer, you'll own the entire lifecycle, from defining the long-term architectural vision to writing the code that brings it to life. You'll manage, mentor, and grow a small group of talented engineers, and improve engineering standards across the wider organisation.

The projects

You'll work on engineering projects that give you scope to own architecture, solve complex problems, and influence how the team grows, while delivering features that matter to customers.

• Service Architecture: Design the architecture and service boundaries of our payments platform to make it scalable, robust, and flexible.
• Authorisation Service: Design and build the service that responds to authorisation requests when customers use their card, ensuring >99.9% successful response rate, <0.5s latency, and capacity to handle 100,000 transactions per day.
• Reward calculation: Develop a real-time rewards platform that supports a diverse range of benefits - such as cashback, points, and travel perks - and displays them to customers instantly as they spend.

The requirements

Essential:

• Experience designing and operating highly available, low-latency payments systems (10,000+ transactions per day).
• Proficiency in an object-oriented programming language, ideally Python.
• Experience designing data models for payments systems, ensuring accuracy, scalability, and maintainability, ideally using PostgreSQL.
• Experience building and integrating APIs and distributed systems, including microservices.
• Experience mentoring engineers and setting technical standards.
• Clear, concise written and verbal communication, prioritising the most relevant information and focusing on outcomes and impact.

Bonus:

• Technical knowledge of card network transaction flows.
• Experience with financial ledgers.
• Experience with Django.
• A strong numerical or technical background, ideally with a degree in maths, physics, computer science, engineering, or a related field.

The salary

We expect to pay from £100,000 - £140,000 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

We put a lot of effort into making iwoca a brilliant place to work:

• 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

We offer:

• 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.