Software Engineer - Kotlin & Coroutines, OUTSIDE IR35, REMOTE

Senior Software Engineer - Kotlin & Coroutines. £500/day LTD CO OUTSIDE IR35. 100% REMOTE. An interest in AI (Agentic AI, AI tooling, Claude, Codex or Co-Pilot) highly advantageous but not essential.

We are looking for a Senior Backend Engineer (Kotlin & Coroutines essential) to build the integrations that connect AI companion with senior care and hospital software platforms.

In this role, you will design, build, and maintain robust Back End services and integrations that enable seamless data exchange between the company and partner systems. You'll take end-to-end ownership of integration projects-from discovery and architecture through implementation, deployment, and continuous improvement.

Key Responsibilities for the Kotlin & Coroutines Developer are:

• Design, develop, and maintain integrations between my clients platform and third-party healthcare and senior care software systems.
• Build scalable, secure, and maintainable Back End services and APIs using Kotlin.
• Design and implement RESTful and/or GraphQL APIs following industry best practices.
• Take full ownership of integration projects, from solution design through implementation, testing, deployment, and ongoing enhancement.
• Develop thoughtful data models and architecture that support complex healthcare workflows and long-term scalability.
• Collaborate closely with product managers, engineering teams, customers, and integration partners to deliver high-quality solutions.
• Help define engineering standards, best practices, and technical direction for Back End integrations.
• Contribute to improving documentation, reliability, and performance across integration services.

Technical Skills

• Several years of professional Back End software engineering experience.
• Strong commercial experience developing applications in Kotlin.
• Excellent understanding of Kotlin Coroutines and asynchronous programming.
• Experience designing, developing, and maintaining RESTful APIs and/or GraphQL APIs.
• Experience integrating with third-party systems and external APIs.
• Strong understanding of scalable Back End architecture and API design principles.
• Experience designing sustainable data models for complex business domains.