Senior Backend Software Engineer with Kotlin

About the role

We are looking for a Senior Backend Software Engineer to design, build, and operate backend services for an internal platform that leverages decisioning and machine learning to deliver personalised customer experiences. This senior individual contributor role focuses on Kotlin, APIs, PostgreSQL, cloud technologies, streaming, and distributed data processing, delivering backend capabilities end‑to‑end while collaborating closely with frontend and data teams.

Key responsibilities

• Design, build, maintain, and operate backend services and REST APIs using Kotlin and Ktor.
• Own backend work from discovery through implementation, testing, deployment, observability, and production support.
• Model and manage data in PostgreSQL, including schema design, performance tuning, and migrations.
• Use Terraform to define and provision cloud infrastructure as code.
• Build event‑driven and batch data‑processing workflows with Kafka and Spark.
• Collaborate with data scientists and other teams to integrate machine‑learning systems.
• Improve service resilience, security, logging, metrics, tracing, and operational tooling.
• Contribute to technical design, code reviews, documentation, and maintainability of a large codebase.

Required profile

• BSc/MSc in Computer Science or related field.
• 6‑8+ years of software engineering experience, strong backend development with Kotlin/Ktor or other JVM languages.
• Proven experience designing, delivering, and maintaining production APIs and distributed services.
• Strong relational database and SQL skills, including data modelling and performance optimisation.
• Experience with asynchronous programming, concurrency, event streaming, and resilient integration patterns.
• Hands‑on experience with cloud‑native applications, containers, managed services, and infrastructure‑as‑code (Terraform).
• Demonstrated ability to own substantial backend work and make trade‑offs between delivery, maintainability, reliability, and performance.

Required skills

• Kotlin
• Ktor
• Java
• PostgreSQL
• Kafka
• Avro
• Spark
• Scala
• Python
• AWS
• GCP
• Docker
• Terraform
• GitLab CI/CD
• Kotest
• Property‑based testing
• Cucumber
• Playwright
• OpenTelemetry