Freelance Senior Software Developer (Kotlin) - AI Trainer

What this opportunity involves

• Design and maintain automated tests to ensure the quality, performance, and reliability of Kotlin and Android applications.
• Collaborate with developers to identify, reproduce, and resolve functional, performance, and UI issues across multiple environments.
• Define and improve quality standards across build pipelines, ensuring smooth CI/CD integrations and release stability.
• Monitor app behavior in production and use data‑driven insights to guide testing priorities and improvements.
• Apply professional judgment to assess AI responses.

What we look for

• Degree in Computer Science, Software Engineering or related fields.
• 5+ years of Kotlin including coroutines, extension functions, and sealed classes.
• 3+ years of Android/JVM development experience.
• Familiarity with JUnit 5, Kotest, MockK, and Android testing (Espresso, Robolectric).
• English proficiency - B2
• Stable internet connection

Project time expectations

Tasks for this project are estimated to take 6-10 hours to complete, depending on complexity. This is an estimate and not a schedule requirement; you choose when and how to work. Tasks must be submitted by the deadline and meet the listed acceptance criteria to be accepted.

Payment

• Paid contributions, with rates up to $40/hour*
• Fixed project rate or individual rates, depending on the project
• Some projects include incentive payments