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

Salt; Greater London; Hybrid; GBP 92,000 - 129,000; Full time

Job summary

Salt Digital Recruitment in London is seeking a hands-on Senior Full Stack Developer specializing in Kotlin and React for a Banking project. You will collaborate across business and tech to ship frequent releases and influence product and technical direction in an XP environment.

This role is hybrid—3 days in the office—with start ASAP. The contract spans 6–12 months, priced at daily rates of £500–£700 inside IR35; overall compensation depends on experience and client requirements.

Qualifications

• 10+ years of professional software development with JVM languages.
• Experience with Kotlin/Java/Scala and frontend ReactJS.
• Proven XP/agile practices: TDD, pair programming, CI/CD.
• Ability to design and implement full-stack solutions.

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; monitor production services.

Skills

Kotlin development

Java/Scala

TypeScript

ReactJS

XP/Agile practices

TDD

CI/CD

GitHub Copilot

DevOps mindset

Job description

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.

Key Responsibilities

• 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

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