Senior Kotlin Developer
Posted 3 days ago by Salt
£900 Per day
Inside
Hybrid
London Area, United Kingdom
Summary: The Senior Kotlin Developer role involves supporting and extending a cloud-hosted platform for bookbuilding issuances within Investment Banking Capital Markets. The position requires hands-on engineering with a focus on Extreme Programming practices and collaboration within a high-caliber front office engineering team. The successful candidate will contribute to development, integration, and production support while maintaining high standards of code quality and system reliability. This role is based in London with a hybrid working arrangement and is classified as inside IR35.
Key Responsibilities:
- Support and extend a cloud-hosted platform for bookbuilding issuances.
- Contribute to development, integration, and production support.
- Collaborate closely with team members to maintain high standards of code quality and system reliability.
- Engage in hands-on engineering practices, including mob programming and test-driven development.
- Support the platform in production, using incidents and defects to improve system design.
Key Skills:
- Strong commercial experience building backend services using Kotlin.
- Experience with event-sourced and event-driven architectures.
- Deep familiarity with Extreme Programming practices.
- Cloud experience with GCP, including GKE and/or Cloud Run.
- Experience with CI/CD and SDLC in regulated or enterprise environments.
Salary (Rate): £900 daily
City: London
Country: United Kingdom
Working Arrangements: hybrid
IR35 Status: inside IR35
Seniority Level: Senior
Industry: IT
Senior Kotlin Developer (XP, GCP) – Investment Banking – London/Hybrid
Daily rate: £700 - £900 (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