Kotlin Service & Concurrency Reviewer
Job Description
Work at IXO
Apply your experience in Kotlin backend engineering to paid work at IXO. You will develop realistic evaluation examples and review AI responses for technical correctness, clear reasoning and practical usefulness. The work calls for explanations that identify the actual defect or trade-off and show how a better answer would address it.
Responsibilities
• Review Ktor, Kotlin Spring Boot and Micronaut implementations for sound server-side design.
• Assess coroutines, Flow, structured concurrency, nullability, sealed classes and type-safe DSL patterns.
• Evaluate persistence with Exposed, jOOQ or JPA, migrations and Kotest or MockK strategies, including JVM-interoperability and exception-flow errors.
• Record the assumptions, supporting evidence and corrections needed for another specialist to follow your review.
Experience and expertise
• 6• years on JVM backends, including 3• years writing production Kotlin server code.
• Practical depth in at least one major Kotlin web framework (Ktor or Spring Boot).
• A thorough understanding of coroutines, Flow, and structured concurrency in production systems.
• Experience with relational and document databases on the JVM.
• Ability to work confidently with Gradle, build scripts, and multi-module Kotlin projects.
• Familiarity with cloud deployment (AWS, GCP) and observability is an advantage.
Working arrangements and pay
Remote work in these eligible locations: USA, UK, Germany, Netherlands, Canada. Planning availability: Flexible, 10-25 hours/week. IXO will confirm the actual start and schedule before acceptance. Compensation is $85 • $135/hr USD. The agreed rate, delivery requirements and review criteria are confirmed before work begins.