Senior Kotlin Engineer (XP, GCP) - Investment Banking - London
Senior Kotlin Engineer (XP, GCP) - Investment Banking - London/Hybrid
Daily rate: £600 - £800 (inside IR35)
Duration: 6 months
Start: ASAP
My client is looking for an experienced Senior Kotlin engineer to support and extend a cloud-hosted platform used for bookbuilding issuances within Investment Banking Capital Markets. You will join a high-calibre London-based front office engineering team working on a next-generation issuance platform replacing a legacy bookbuilding system.
This is a hands-on engineering role with a strong emphasis on Extreme Programming (XP) practices, including mob programming, test-driven development, and continuous refactoring. Engineers are expected to contribute across development, integration, and production support, collaborating closely to maintain high standards of code quality, system reliability, and performance.
Required & Desirable Skills
- Strong commercial experience building backend services using Kotlin
- Experience with event-sourced and event-driven architectures
- Deep familiarity with XP practices, including:
- Mob programming as a primary way of working
- Test-driven development (TDD)
- Continuous refactoring and clean code principles
- Cloud experience with GCP, including:
- GKE and/or Cloud Run
- Cloud SQL and Memory store
- Artifact Registry and Cloud Logging
- Key Management
- Experience with CI/CD and SDLC in regulated or enterprise environments
- Comfortable working on production systems requiring high availability and accuracy
Engineers in this role:
- Work primarily in mobs, sharing ownership of design and code
- Build, test, and evolve services with a strong focus on clarity, simplicity, and maintainability
- Support the platform in production, using incidents and defects as opportunities to improve system design and resilience
*Rates depend on experience and client requirements