Senior Kotlin Engineer

ClientOur 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 overviewThe 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.ResponsibilitiesDesign, 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.Requirements5+ 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 haveExperience with Kafka.