Full job description Company: Client of Xcelyst
Location: London, UK
Working Model: Hybrid – 2–3 days onsite per week
Salary: Up to £105,000 per annum
Employment Type: Fixed-Term Contract
Role Overview Our client is looking for an experienced Kotlin Developer to work on a strategic technology programme for a leading global financial-services client in London.
The successful candidate must have strong, hands-on experience in core Kotlin development and be comfortable designing, developing and supporting secure, scalable backend applications within a complex enterprise environment.
Key Responsibilities *Design, develop and maintain backend applications using core Kotlin.
*Produce clean, reusable, testable and maintainable code.
*Develop scalable APIs, services and business components.
*Participate in application design and technical architecture discussions.
*Troubleshoot application, performance and production issues.
*Write unit and integration tests to maintain high engineering standards.
*Participate in code reviews and contribute to development best practices.
*Collaborate with developers, architects, business analysts and product teams.
*Work within an Agile delivery environment.
*Support the continuous improvement and modernisation of existing platforms.
Essential Skills *Strong commercial experience in hands-on Kotlin development.
*Excellent understanding of core Kotlin concepts, including coroutines, collections, null safety and functional programming.
*Strong backend development and API engineering experience.
*Experience with Spring Boot or similar backend frameworks.
*Good understanding of microservices and distributed application architecture.
*Strong knowledge of REST APIs, databases and system integrations.
*Experience with automated testing, preferably TDD.
*Familiarity with CI/CD pipelines and cloud-based development environments.
*Strong problem-solving and communication skills.
*Experience working in Agile engineering teams.
Desirable Skills *Previous experience within banking, financial services or capital markets.
*Experience developing high-volume or business-critical applications.
*Exposure to cloud platforms such as GCP, AWS or Azure.
*Knowledge of containerisation and orchestration technologies.
*Experience with event-driven systems and messaging platforms.
Interview Process The selection process consists of two stages:
*Virtual technical interview
*In-person interview in London
Candidates must be comfortable working onsite in London for 2–3 days per week.