Senior Engineer (Customer Auth)

Small businesses are the backbone of the economy, and we’re here to help them win. We’ve built a platform that uses clever data to get them the funding they need in minutes, not weeks.

At Funding Circle, we have the restless energy of a fintech start-up with the stability of a public company. It’s a unique mix that gives Circlers the autonomy to take ownership and the scale to make an impact that truly counts.

We’re a high-performing team that chooses to lift each other up. We challenge, we champion, and we have each other’s backs - because we know that when we stand together, we move faster and build better.

The impact is real: Last year alone, the businesses on our platform generated £7.2bn for the UK economy 📈 Come and join a mission that matters!

[Read our Impact Report] | [See our Trustpilot]

📍 London (Hybrid) | 🤝 2 days in the office | 💰 Competitive Salary + Benefits

We are looking for a Senior Engineer in our Customer Auth team. The Customer Auth team builds the foundational security and identity platforms that power Funding Circle's transition to a modern, distributed architecture. We own the critical systems responsible for securing customer access and managing complex business relationships for all product teams.

• You will build, run and maintain authentication and authorisation systems

• You will take a product scope, design the technical solution and deliver it

• You will work closely with Product and with other engineering teams who use your systems

• You love to build new things - much of the team's work is greenfield - but also don’t shy away from digging into older codebases

• You love to work in a complex problem domain that is implemented with simple software systems.

• You are a collaborator - you encourage pairing and believe that working together is smarter than working in a silo

• You are a teacher - generous with your time and expertise to teach stakeholders and our fellow engineers how to answer their own questions

Hear from our Software Engineer, Judith, about what its like to be part of our Product Engineering team!

We value deep expertise, but a growth mindset and good energy are what really make our team click. We’re a group that chooses to lift each other up and think smart every day.

• Experienced in Python

• A senior who is able to lead and influence architectural decisions whilst mentoring and up-skilling more junior engineers

• A strong fundamental programmer with experience in distributed systems Familiar with developing with AWS, Kubernetes, Kafka and serverless

• Knowledgeable of Agile, TDD and CI/CD

• Excellent communication skills, both written and spoken

• Engages actively and collaboratively with team members and stakeholders

• Able to architect custom AI solutions and smart automated systems that are safe, maintainable, and aligned with our long-term mission

• Act as a technical bridge and mentor, training “builders" across the company to move from basic AI usage to sophisticated system creation.

We’re building a place where everyone truly feels they belong. Even if your past experience doesn't align perfectly with every requirement, we'd still love to hear from you.

We back you to build an incredible career and by joining us, you'll be part of one of The Sunday Times Best Companies to Work For 2026! As a flexible-first employer, we use a "best of both" approach. We’ll see you in our London office to collaborate – with barista coffee and subsidised Just Eat lunches on us!

Our Circler Proposition focuses on five areas:

• Flexibility: We provide a benefit allowance you can tailor to your own life and family.

• Health: This includes private medical and dental, health assessments, and access to a digital GP.

• Wealth: We offer life assurance, share schemes, and financial coaching.

• Development: You get a dedicated annual learning allowance to help you level up.

• Lifestyle: We have electric car and cycle-to-work schemes, plus season ticket loans.

We also have award-winning parental leave policies. We're here to support you through the big life moments, from fertility treatments to new additions to the family.