Senior Backend Engineer - Java in London

This job is brought to you by Jobs/Redefined, the UK's leading over-50s age inclusive jobs board. LemFi (Series B) is building the go-to financial app for the Global South. Moving to a new country shouldn't mean starting from zero. That's why our team of 400+ spanning 20+ countries is building a financial ecosystem that helps immigrants stay connected to home, build stability, and create wealth regardless of where they are from or where they live.

What began as fast, affordable remittances is now evolving into a complete platform for multi-currency accounts, payments, credit, and long-term financial growth. With over 2 million users across the globe, we process over $1.5B in monthly transactions to 30+ countries, proving that borders shouldn't limit financial opportunity.

The Role

You will be the engine behind our global expansion. Your primary focus will be integrating high-value payout partners and launching new currency corridors that allow our users to send money anywhere, instantly. You won't just be connecting APIs; you will architect the abstraction layers that normalise money movement across fragmented global banking systems, ensuring that a transaction to Nigeria feels just as seamless as one to Brazil or the Philippines.

How You’ll Contribute

• Architect & Build: Design and ship scalable, secure, and cloud-native backend features with a focus on simplicity, data consistency, and financial privacy.
• Own the Lifecycle: Take end-to-end responsibility - from technical design and documentation to gradual rollouts and on-call rotation (“you build it, you run it”).
• Ensure Reliability: Uphold rigorous standards through automated testing, clean code practices, and proactive monitoring of SLAs and SLOs.
• Drive Cross-Functional Impact: Partner with teams outside of engineering to deliver compliant financial products that align with customer needs and regulatory standards.

Who You Are

• Impact-Driven: You prioritise solving real business problems with reliable, maintainable code over just closing tickets.
• Technically Grounded: You have strong experience building scalable backends in Java, making smart architectural trade-offs.
• High Ownership: You don’t wait to be told what to do. You take full responsibility for your systems from design to deployment.
• Collaborative: You communicate clearly with Product and Engineering, prioritising shared success over individual credit.
• Curious: You actively seek feedback and look for ways to improve both your skills and the broader system.

What You’ll Bring

• 5+ years building backend systems in Java.
• Strong command of PostgreSQL (optimisation/isolation) and Redis.
• Experience with async workflows (Kafka, co-routines) and DDD.
• Proficiency with Docker, observability stacks, and REST principles.
• Bonus: CI/CD experience (GitHub Actions) & a CS Degree.

The Interview Process

• Chat with a Talent Partner (30 mins)
• Behaviours & Culture (60 mins)
• Pair Programming (90 mins), System Design (30 mins)
• Final Interview (30 mins)

Why Join LemFi?

Love shouldn’t be expensive, yet those working hardest for their families often face predatory fees and banking exclusion. We’re changing this. At LemFi, you won’t be just a cog in a machine. Whether designing products, scaling operations, or telling our story, you’ll tackle complex challenges with real, immediate impact. Your work goes beyond metrics - it puts money back in families’ pockets and offers access to the previously excluded. Join us to make a meaningful difference, where high performance is a lifeline for millions.

Our Values: How We Win

• Sharp Customer Focus: We cut through the noise and prioritise ruthlessly based on what drives real value.
• Lead with Data: We trade instinct for insight. We test, analyse, and own the outcomes.
• Ownership: We take responsibility for global outcomes, not just local wins.
• Grit: We navigate ambiguity with resilience and keep pushing until the customer feels the impact.

Diversity & Inclusion at LemFi: To build the best financial tools for the global diaspora, we need a team that reflects the world we serve. We welcome builders from all walks of life who embody our values over a perfect resume. Don’t meet every single requirement in the job ad? Research shows that candidates from underrepresented backgrounds often hesitate to apply if they don’t check every box. If you are excited about this role and our mission, we encourage you to apply anyway. You might be just the right person for this, or other roles.