Lead Full-Stack Engineer

Let me introduce...
With Sonia, doctors are successful doctors. We create and deploy AI-enhanced solutions that make doctors' lives easier, patients' care better, and healthcare systems more efficient. If you're proactive, impact-driven, and ready to shape the future of healthcare, join us.

We're looking for a
Lead Full-Stack Engineer (all)
to drive the development of our modern, high-performing web applications. You'll take ownership of technical direction, lead a team of engineers, and ensure our product remains scalable, reliable, and thoughtfully built.

This role can be performed in a hybrid setup from our offices in
Luxembourg
or
Berlin
, or remotely from anywhere in Germany or Luxembourg.
This Is What You'll Own

• Team Leadership: Lead, coach, and develop a team of full-stack engineers, fostering growth, clarity, and high performance.
• Application Development: Design and implement robust, scalable full-stack web applications.
• Code Quality: Ensure clean, maintainable, and testable code that meets high engineering standards.
• Architecture: Steer architecture decisions and long-term technical planning together with other leads.
• Performance: Optimize application performance and system reliability across the stack.
• Mentorship: Enable skill development, support career growth, and model best practices.
• Review & Feedback: Conduct thoughtful code reviews and drive a culture of constructive feedback.
• Documentation: Contribute to technical documentation and cross-team knowledge sharing

You'll thrive in this role if you bring
Must Haves

• Experience: 8+ years of professional software development experience.
• Leadership: Proven experience leading or mentoring engineers.
• Fundamentals: Solid understanding of full-stack development principles.
• Core Expertise: Strong expertise in TypeScript / JavaScript and
• Frontend: Advanced experience with React and modern front-end development.
• Database Layer: Hands-on experience with ORM tools, especially Prisma.
• Backend: Extensive experience in backend development with
• APIs: Strong experience with RESTful API design and implementation.
• Data Modeling: Experience with database schema design and data modeling.
• DevOps Foundation: Understanding of CI/CD pipelines and deployment workflows.
• Platform Ops: Familiarity with container orchestration and GitOps workflows, ideally with Kubernetes and tools like Argo CD.
• Version Control: Proficiency with Git version control.

Nice to Have

• Frameworks: Experience with or other server-side rendering (SSR) frameworks.
• UI Libraries: Familiarity with Chakra UI.
• Testing: Experience with testing frameworks (e.g., Playwright, Vitest).

Why you'll love working with us

• An engineering-driven culture with modern tools and clean code practices.
• A product-focused environment where quality and performance matter.
• A collaborative team that values learning, pragmatism, and ownership.
• Attractive compensation aligned with your skills.
• Flexible work arrangements.
• 30 days of vacation per year.
• The chance to work on products that directly shape the future of healthcare.

Ready to apply?
If you enjoy building meaningful applications, driving technical excellence, and contributing to the transformation of healthcare, we'd love to hear from you

I'm Margarita and will be guiding you through the application process.

About Us
At Sonia, we're building more than just a product — we're building a team that helps doctors succeed with the power of AI. To grow and shape the future of healthcare, we're looking for people who want to create, challenge, and collaborate — and have fun while doing it.

We believe teams thrive when different perspectives come together and work toward a shared goal.
We welcome and respect everyone for who they are, regardless of origin, gender, age, religion, disability, or sexual identity. We're excited to meet people from all backgrounds who want to bring their unique perspective to our mission.

Are you in?