​Full-Stack Engineer (Kotlin/Spring Boot + React Native)

(!)Please note: This position is open to EU-based candidates only.

Job Description:

Middle/Senior Full-Stack Engineer

Role Type: Generalist / Execution & Support

Focus: Feature Development (Backend/Web/Mobile), Maintenance, Support

Role Summary:

We are looking for a versatile Full-Stack Engineer to handle the day-to-day development and maintenance of the Ionnyk ecosystem. You will step into a role that touches every part of our product: the mobile app used by clients, the web portals for administration/B2B, and the backend services. You will also play a crucial role in maintaining system stability and supporting our internal teams.

Key Responsibilities:

• Software Development (Full-Stack & Mobile): Develop, maintain, and implement RESTful Web Services using Kotlin and Spring Boot, leveraging JPA (Hibernate) and PostgreSQL with Flyway for database management. Build and maintain user-facing web interfaces using React, TypeScript, and Redux Toolkit. Maintain and evolve the mobile application using React Native and Expo, including handling BLE integrations for device communication. Manage third-party integrations (Stripe, HubSpot).

• DevOps & Infrastructure: Develop and maintain the GCP infrastructure, Kubernetes orchestration, and GitOps deployments via FluxCD. Assist with the integration and deployment process, demonstrating familiarity with GitLab CI/CD pipelines and Docker containerization.

• Technical Support & Tooling: Provide L2/L3 support, including analyzing bugs in the GCP console, and troubleshooting specific issues for the Customer Support team. Manage internal IT tools (Google Workspace, Slack, Scripts) to keep operations running smoothly.

• Code Quality: Adhere to best practices for code quality, testing, and continuous integration.

Required Competencies:

• Full-Stack Expertise:

• Expert in either Backend (Kotlin/Spring Boot) or Web Frontend (React/TypeScript) with Advanced skills in the other.

• Advanced knowledge of Kotlin and Spring Boot 3.x.

• Advanced knowledge of React (hooks, context) and TypeScript.

• Versatility: Willingness to switch between fixing a UI bug in React, debugging a Kotlin API endpoint, and analyzing a log in Google Cloud.

• Web/Frontend:

• Strong proficiency with React and Redux Toolkit.

• Familiarity with modern tooling: Vite, Tailwind CSS, and Material-UI (MUI).

• Mobile (React Native):

• Experience with React Native, Expo, MobX, and deploying to iOS/Android.

• Intermediate experience with State Management (Redux Toolkit or MobX).

• Data:

• Intermediate proficiency with PostgreSQL and comfortable with writing SQL queries.

• Familiarity with database migration tools like Flyway.

• Cloud & DevOps:

• Knowledge of Google Cloud Platform (GCP), Docker, Kubernetes, and CI/CD pipelines (GitLab CI).

• Basic understanding of Docker and continuous deployment practices.

• Nice-to-Haves/Bonus:

• Experience with Firebase Auth.

• Experience with Bluetooth Low Energy (BLE) libraries.

​What’s in it for you:

• ​Strategic Impact: Direct influence on the tech roadmap and the evolution of the Ionnyk ecosystem.

• ​Modern Stack: No legacy. Work with Kotlin 1.9+, Spring Boot 3.x, React, Expo, and K8s.

• ​Innovation: Build at the intersection of IoT, Art, and Cloud (E-paper & BLE technology).

• ​Infrastructure Ownership: Full autonomy over GCP infrastructure and GitOps (FluxCD) deployments.

• ​Flexibility: Remote or Hybrid work model with a focus on results, not micromanagement.

• ​Package: Competitive salary and the best hardware for your setup.