Staff Back End Engineer - Finance Technology

Hybrid in London (UK) or Remote within the UK

We’re looking for a Staff Back-End Engineer

You’ll combine deep technical knowledge with business context to help us launch a credit card and scale our financial systems.

The company

Small businesses move fast. Opportunities often don’t wait, and cash flow pressures can appear overnight. To keep going, and growing, SMEs need finance that’s as flexible and responsive as they are.
That's why we built iwoca. Our smart technology, data science and five-star customer service ensures business owners can act with the speed, confidence and control they need, exactly when it's needed.
We’ve already cleared the way for 100,000 businesses with more than £4 billion in funding. Our passionate team is driven to help even more SMEs succeed, through access to better finance and other services that make running a business easier. Our ultimate mission is to support one million SMEs in their defining moments, creating lasting impact for the communities and economies they drive.

The team

The Finance Technology team builds and maintains the payment infrastructure and financial data systems that power iwoca’s growth. We partner with Finance to build scalable tools and support other product teams to launch new products with the right payment and data foundations. The team is currently six engineers working closely with a Tech Lead and Product Manager, using Agile methods to ship code frequently and solve complex problems together. Three of the team work remotely and five are hybrid, based in London.

The role

As a Staff Back End Engineer in the Finance Technology team, you’ll lead the technical design and development of iwoca’s financial data systems, starting with a new credit card ledger — a critical component for product expansion. You’ll work with stakeholders across Finance to shape architecture, ensure accuracy and scalability, and mentor engineers while staying hands-on with code.

The projects

You’ll work on engineering projects that give you scope to own architecture, solve complex problems, and influence how iwoca’s financial systems evolve, such as:

• Credit card ledger: Scale a new ledger system to process hundreds of thousands of daily transactions with precision and resilience, enabling accurate real-time reporting and reconciliation.

• Payments infrastructure: Extend and improve the systems that power real-time payments, ensuring reliability, scalability, and seamless integration with new products.

• Financial data systems: Build and maintain services that provide Finance, Accounting, and Capital Markets teams with accurate, timely data for reporting, planning, and compliance.

• Technical leadership: Guide engineers through complex design decisions, mentor team members, and set standards that raise quality, documentation, and performance across the group.

The requirements

Essential:

• Experience designing and building scalable back-end systems for payments or financial ledgers.

• Proficiency in Python, writing clean, efficient, and well-tested code.

• Experience designing data models for payments systems, ensuring accuracy, scalability, and maintainability, ideally using PostgreSQL.

• Experience architecting highly available systems that process large transaction volumes (10,000+ per day).

• Experience leading projects end to end, from scoping and design through to production.

• Experience mentoring engineers and setting technical standards.

• Clear, concise written and verbal communication, focusing on outcomes and impact.

• Numerical or technical background, ideally with a degree in maths, physics, computer science, engineering, or a related field.

Bonus:

• Experience with Django.

• Experience with infrastructure-as-code and CI/CD pipelines.

• Experience with Rust.

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 performance and salary 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 thought and skill diversity, and encourage you to explore new areas of interest to help us innovate and improve our products and services.

The offices

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

• Offices in London, Leeds, Berlin, and Frankfurt with plenty of drinks and snacks

• Events and clubs, like bingo, comedy nights, football, etc.

The benefits

• Flexible working hours

• 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 per year, 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 external counselling and therapy sessions for team members that need emotional or mental health support

• 3% Pension contributions on total earnings

• An employee equity incentive scheme

• Generous parental leave and a nursery tax benefit scheme to help you save money.

• Electric car scheme and cycle to work 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