Our client is seeking a Senior Back-End Engineer (Kotlin) to support the modernization and evolution of a core services platform. This role will focus on building, maintaining, and supporting backend services developed in Kotlin using the Micronaut framework, while contributing to architectural design and implementation planning alongside senior technical leaders.
The position operates within a mission-driven organization where quality, reliability, and customer impact are critical. The engineer will participate in modernization initiatives and may also support limited frontend development as part of a broader full-stack environment.
**About First Factory**
We are a software development company with over two decades of experience, boasting a dynamic team of 175+ professionals actively engaged in diverse projects across various industries. We invite you to join us on this journey as we thrive and embrace fresh challenges.
**Key Responsibilities**
- Design, develop, maintain, and support backend services built with Kotlin and Micronaut.
- Collaborate with lead and senior engineers to define architectural solutions and execute implementation stories.
- Contribute to modernization initiatives for legacy systems, particularly within regulated or enterprise environments.
- Ensure high standards of code quality, performance, scalability, and maintainability.
- Participate in technical planning, design discussions, and problem-solving activities.




- Support troubleshooting and resolution of complex technical issues in development and production environments.
- Follow best practices for secure software development, testing, and documentation.
- Demonstrate strong ownership of deliverables and alignment with organizational values and service quality expectations.
**Requirements**:
- 5+ years of professional experience developing web services using Kotlin and Micronaut.
- Strong backend development experience building and supporting scalable service-based architectures.
- Experience working with Spring Boot (acceptable alternative or complementary framework).
- Solid understanding of RESTful API design and service integration.
- Experience contributing to architectural design and implementation planning.
- Strong problem-solving skills and attention to detail.
- Excellent communication skills and ability to collaborate effectively with senior engineers and stakeholders.
**Nice to have**
- Experience with agentic coding tools or AI-assisted development tools such as Claude Code, OpenAI Codex, or similar platforms.
- Knowledge of prompt design and practical integration of AI tools into development workflows.
- Experience modernizing legacy systems, particularly in legal, financial services, or other regulated domains.
- Frontend experience using Next.js and TypeScript, or willingness and ability to grow into a broader full-stack role.
- Background in building or supporting enterprise platforms for financial services.

📌 Senior Back End Engineer (Kotlin) (Ciudad de México)
🏢 First Factory
📍 Ciudad de México