Interim Senior Software Lead Kotlin £1200 p/d

Rate: £1000-1200 p/d (Inside IR35)

Duration: 6-month Contract

Location: London (Hybrid)

Client: Investment Banking Technology

An Interim Senior Software Engineer to join a high-performing front-office engineering team delivering a next-generation cloud-native issuance platform for global capital markets.

This platform is replacing a legacy bookbuilding system used by investment banking teams worldwide and supports high-volume, real-time workflows during critical trading windows. The engineering environment is collaborative, fast-paced, and strongly aligned to Extreme Programming (XP) principles.

The Role

The lead Software Engineer will have senior-level experience in Kotlin and Event-sourcing, and business communication skills. You will leverage your Kotlin and event sourcing expertise within the team, as well as communicating with business users, without proxy.

This is a senior engineering position focused on designing, building, and evolving backend services in Kotlin within a modern cloud-native architecture.

You will work closely with engineers, product specialists, and business stakeholders to deliver resilient, scalable solutions that support real-time issuance and allocation workflows.

The role places strong emphasis on:

• Mob programming
• Test-driven development (TDD)
• Continuous refactoring
• Collective ownership
• Incremental delivery
• Production excellence

Required Skills & Experience

• Extremely senior-level Kotlin experience
• Event-sourcing, and business communication skills
• Ability to leverage Kotlin sourcing expertise with the team and communicate well with business users
• Strong commercial experience building backend services using Kotlin
• Deep understanding of event-driven and/or event-sourced architectures
• Extensive experience with XP engineering practices
• Strong cloud engineering experience within GCP environments
• Experience working within regulated or enterprise-scale environments
• Comfortable supporting high-availability production systems

This is an opportunity to work on a business-critical platform used globally, within a modern Cloud-native engineering environment.

Note: Applicants must hold current and valid UK Right to Work

If interested, please apply asap and any questions, email claire.shipman@1st-executive.com