Senior Full-Stack Engineer (Kotlin/React) – Hybrid

Zühlke Engineering; Greater London; Hybrid; GBP 51,000 - 91,000; Full time

Job summary

Zühlke Engineering is seeking a backend engineer in London or Manchester to build and maintain JVM-based services using Kotlin or modern Java, and to design APIs that power responsive web interfaces.

You will work in a cross-functional squad, apply test-driven practices, and explore AI-assisted tools to improve tests, documentation, and systems while ensuring security, reliability and performance. Occasional client-site work is expected.

Qualifications

• Strong commercial experience building server-side apps with Kotlin/Java.
• Good knowledge of JVM ecosystem and backend practices.
• Experience designing, building and operating APIs.
• Understanding of reliability, performance, security.
• Proven ability to write effective automated tests.
• Practical experience with relational databases.
• Frontend experience with React/TypeScript is a plus.
• Familiar with CI/CD and production support.
• Experience in agile, product-focused teams.
• Interest in AI-augmented engineering and new ways of working.
• Commitment to code quality and continuous improvement.

Responsibilities

• Build and maintain JVM-based services using Kotlin or modern Java.
• Design, develop and document APIs and integrations.
• Contribute to API design standards and docs.
• Deliver end-to-end features with backend services and responsive UI.
• Apply test-first or test-informed practices for automated tests.
• Explore AI-assisted tools where value is clear and safe to use.
• Validate AI outputs for correctness, security and maintainability.
• Contribute to event-driven workflows and asynchronous processing.
• Engage in technical discovery, spikes, architecture discussions and code reviews.
• Improve build, test and deployment pipelines for safe delivery.
• Embed logging, metrics and tracing for operability.
• Consider security and governance in engineering decisions.
• Address technical debt and reliability risks.
• Share knowledge and support a collaborative team culture.
• Work with clients on-site when required to shape solutions and support delivery.

Skills

Kotlin

Java 17+

JVM ecosystem

API design

Automated testing

Relational databases

React

TypeScript

CI/CD

Agile

AI curiosity

Code quality

Tools

Ktor

Spring

Spring Boot

React

TypeScript

AWS

Azure

GCP

NoSQL

SQL

Quarkus

Job description

Zühlke Engineering is seeking a backend engineer in London or Manchester to build and maintain JVM-based services using Kotlin or modern Java, and to design APIs that power responsive web interfaces.

You will work in a cross-functional squad, apply test-driven practices, and explore AI-assisted tools to improve tests, documentation, and systems while ensuring security, reliability and performance. Occasional client-site work is expected.