FullStack Software Engineer

CoreWillSoft GmbH is a German-based company working on secure IoT software solutions and services. The mission of CoreWillSoft is to help businesses protect their assets, employees, and data by providing advanced software solutions and services in the security industry.

We are looking for a Full-Stack Software Engineer with strong backend experience in Kotlin/Java and either:
solid Frontend (React) expertise, or
experience in Kotlin Multiplatform / Android development

You will work on products used by businesses across Western Europe and North America.
Our team operates in a scaled agile approach across Europe with a headquarter in Bonn, Germany. It is responsible for the complete software development lifecycle; including ideation, implementation, and operation of the secure IoT software operating smart buildings and smart homes across the world.

This is an exciting opportunity to work on cutting-edge projects involving high-security hardware and technology in a creative, international environment.

We offer:
Meaningful Impact: Build solutions that are used every day by thousands of businesses your work will directly improve real-world security and connected device experiences.
Product & Process Ownership: Help shape not only the product, but also how we build and deliver it your ideas and decisions will have visible impact.
Industry Influence: Contribute to key security standards and best practices, staying ahead of the curve in a fast-evolving industry.
Modern Tech Stack & Hardware: Work with the latest hardware and the tools you need to do your best work.
Time Off & Flexibility: Vacation days, paid sick leave, and public holidays in line with German legislation plus flexibility built around outcomes, not micromanagement.
Learning & Development Budget: We support continuous growth by covering hard and soft skills courses, trainings, and access to e-learning platforms.
Coworking Support: Prefer not to work from home every day? We offer coworking compensation so you can choose the environment that fits you best.
Language Learning Support: Monthly fixed compensation you can use to improve your English or German through the learning format of your choice.
Strong Team Culture: Open collaboration, a flat structure, and thoughtful onboarding your voice is heard, and you can make an impact from day one.

Your skills:

Backend:
Proficiency in Kotlin and/or Java for backend development.
Strong experience with Spring Boot framework.
Experience with Docker and containerized applications.
Familiarity with cloud platforms such as AWS, Azure, or Google Cloud.
Experience in designing and consuming RESTful APIs.
Knowledge of microservices architecture and patterns.
Experience with on-premise and cloud-based deployments.
Proficiency in secure coding practices and understanding of security best Ko practices for backend systems.
Familiarity with scalability strategies and performance optimization in backend services.
Knowledge of monitoring and observability tools (e.g., Prometheus, Grafana, ELK).
Knowledge of cryptography and security
Familiarity with CI/CD processes, including GitHub Actions, GitLab CI, or similar tools.
Experience with version control systems (e.g., Git).
Experience with database technologies, both relational (e.g., PostgreSQL) and NoSQL (e.g., MongoDB).

Frontend (one of the following paths is required)
Option 1 – Web Frontend:

Strong experience with React.js or Angular or Vue
Solid knowledge of TypeScript / JavaScript, HTML5, CSS3
Experience with modern tools (Vite, Webpack, npm, etc.)
Understanding of state management (e.g., Redux)

Option 2 – Mobile / Multiplatform:

Experience with Kotlin Multiplatform and/or Android development
Strong knowledge of Kotlin Coroutines and Flow
Experience with Jetpack Compose (or Compose Multiplatform)
Familiarity with dependency injection frameworks (e.g., Koin)
Experience with networking libraries such as Ktor

Nice to have:
Experience with Kotlin Multiplatform in production
Knowledge of modern Kotlin ecosystem (Coroutines, Flow, Compose, Koin, Ktor)
Knowledge of additional programming languages
Experience with system architecture and distributed systems
Understanding of UI/UX design and performance optimization
Knowledge of building automation or access control systems