Kotlin Developer - Financial Services

Senior Kotlin Engineer – London

I am looking for a Senior Kotlin Engineer to join a high-performing front-office engineering team in London, working on a cloud-hosted platform used within Investment Banking Capital Markets.

This is a hands-on backend engineering role focused on building and extending a real-time issuance platform. The system supports a large global user base during time-sensitive execution windows, where reliability, correctness and performance are critical.

The team works with strong Extreme Programming principles, so this role will suit someone who enjoys collaborative engineering, shared code ownership, test-first development and continuous improvement. You will be expected to work closely with other engineers to design, build, test, integrate and support services in production.

The platform already has foundational services in place, and the next phase of work will focus on expanding core business functionality across areas such as sales workflows, hedging processes and allocation features.

Key Responsibilities

You will be responsible for:

• Building and evolving backend services using Kotlin
• Working with event sourced and event driven architecture
• Contributing to system design, integration and production support
• Working in mobs as a primary delivery approach
• Practising test-driven development and continuous refactoring
• Keeping code clear, simple, maintainable and well-tested
• Supporting a high-availability production platform
• Using incidents, defects and feedback to improve reliability and design
• Delivering in small, testable increments within a collaborative engineering environment

Skills and Experience Required

I am looking for someone with:

• Strong commercial experience building backend services in Kotlin
• Experience with event sourced and event driven systems
• Deep understanding of XP engineering practices
• Strong TDD experience
• Experience with mob programming or highly collaborative development practices
• A disciplined approach to clean code and continuous refactoring
• Cloud experience, ideally with GCP or similar environments
• Experience with services such as GKE, Cloud Run, Cloud SQL, Memorystore, Artifact Registry, Cloud Logging or Key Management
• CI/CD and SDLC experience in an enterprise or regulated environment
• Confidence working with production systems where availability and correctness are essential

Location

London

Ideal Background

This would suit a senior backend engineer who has worked in financial services, capital markets, trading, fintech, banking or another high-availability environment where systems must perform reliably under time-critical conditions.

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