Senior Full Stack Developer (Kotlin, React) - Banking - London in London - Salt Search

Senior Full Stack Developer (Kotlin, React) - Banking - London

Daily rate: £500 - £700 (inside IR35)

Duration: 6 - 12 months

Hybrid: 3 days per week in office

Start: ASAP

We're looking for a hands-on engineer who thrives in a collaborative XP environment and enjoys working across the full stack. You'll partner closely with the business, ship frequent releases, and have a real influence on product and technical direction.

How we build

• XP practices: Test-Driven Development, pair programming, continuous refactoring, trunk-based development, and frequent production releases.

• Human-in-the-loop AI: We use GitHub Copilot to improve quality while keeping humans in control. We iterate in small steps, uphold code quality, and share learnings

• DevOps mindset: Teams own their CI/CD pipelines and collaborate closely with SRE partners to run resilient services in production.

Your key responsibilities

• Design, build, and maintain robust, well-tested software; keep solutions simple and evolvable

• Work directly with the Business to shape product goals and iterate quickly on value

• Willingness to work full stack, Back End and Front End Development.

• Own build and deployment: evolve CI/CD pipelines; support, monitor, and continuously improve production services

• Guide architecture: make pragmatic architectural decisions, improve system design, and reduce complexity over time

• Champion engineering excellence: pair, review, refactor, and share knowledge to raise the bar for the whole team

• Use AI well: apply GitHub Copilot to speed up small, safe iterations; keep humans in the loop; share prompts, patterns, and learnings with the team

Your skills and experience

• Kotlin development, or experience in Java/Scala and a desire to cross train

• TypeScript and ReactJS with experience using a JVM language on the server side (10+ years of professional software development)

• Strong grounding in Object-Oriented and/or Functional programming concepts

• Proven use of XP/agile practices: TDD, acceptance testing, pair programming, continuous integration

• Experience applying iterative development to deliver high-value outcomes in complex domains

• Experience using AI development tools such as GitHub Copilot as part of an iterative, human-in-the-loop workflow. We value developers who use Copilot to accelerate small, frequent iterations, rather than delegating decisions to AI.

• Familiarity with CI/CD, observability, and operating production systems

*Rates depend on experience and client requirements