Senior Kotlin Engineer

Client

Our client, a UK‑based digital bank, delivers innovative and accessible financial solutions for modern consumers. Known for its user-friendly platform and customer‑centric approach, it enables people to manage their finances with ease and transparency. Recent expansions into flexible payment options and new services further strengthen its position as a leader in the UK’s digital banking sector.

Position overview

The client is building the bank of the future using cutting‑edge technologies. This is an exciting opportunity to collaborate on a major rebuild of the technical stack. You will work in a small, agile, and cross‑functional team that solves real‑world problems and collaborates closely with stakeholders and key business users.The working schedule aligns with the UK time zone (9:00 AM to 5:30 PM UK time) and may include participation in on‑call shifts when required.

Responsibilities

• Design, develop, and maintain high‑quality backend services using Kotlin.

• Work closely with cross‑functional teams to define, design, and deliver new features.

• Optimize application performance, quality, and responsiveness.

• Conduct code reviews, write unit and integration tests, and ensure robust code quality with a strong emphasis on Test‑Driven Development (TDD) using frameworks such as Kotest or JUnit.

• Participate in the full software development lifecycle—from concept and design to testing and deployment.

• Use code versioning tools like Git for efficient collaboration.

• Engage in continuous improvement practices and agile methodologies.

Requirements

• 5+ years of software development experience with a focus on backend services.

• Knowledge of Kotlin and its use in a professional environment.

• Proven experience with testing methodologies, including unit and integration testing; hands‑on experience with Test‑Driven Development (TDD) and testing frameworks such as Kotest or JUnit is required.

• Experience with Kotlin‑specific frameworks such as Ktor and Coroutines.

• Solid understanding of microservices architecture and best practices.

• Experience working with PostgreSQL.

• Proficiency with code versioning tools like Git.

• Experience with build tools such as Gradle or Maven (Gradle preferred).

• Experience with Docker and Kubernetes.

• Strong command of English both written and spoken with the ability to contribute clearly to team discussions.

• Effective team player with the ability to work independently.

• Proactive mindset with strong problem‑solving skills.

Nice to have

• Experience with Kafka.