Senior Fullstack TypeScript Developer

About the Role
A fast-growing, self-funded AI SaaS company in Munich is looking for a Senior Full Stack Engineer to help scale an enterprise AI platform toward 1 million users. You'll join a small, product-focused engineering team building secure, scalable systems and intuitive UX that brings AI to the core of the SME sector. This is a high-ownership role where your architectural decisions will directly shape the product's trajectory.
What You'll Do
Own the most complex architectural challenges across the platform — including multi-terabyte data synchronisation and secure sandbox infrastructure.
Architect, build, and ship high-quality full-stack features using React and TypeScript , with a focus on long-term scalability and UX.
Design and implement systems to synchronise and index terabytes of client data while enforcing fine-grained permissions.
Build infrastructure to process millions of LLM calls per month with high reliability and security.
Implement scalable, secure code sandbox solutions capable of spawning thousands of sandboxes per day.
Create base infrastructure and tooling for fast custom integrations so new systems can be connected in hours.
Collaborate on technical roadmaps and align on architectural decisions with the broader engineering team.
Debug production incidents, identify root causes, and implement durable fixes to keep the platform stable.
Mentor junior engineers and raise the bar through constructive, thorough code reviews.
Continuously improve development processes, code quality standards, and overall team performance.
What We're Looking For
Required:

• 5+ years of professional experience with React and TypeScript (dealbreaker).
• 7+ years of overall professional software engineering experience.
• 2+ years of backend development experience (Node.js/Express or equivalent).
• Proficiency with containerisation and orchestration using Kubernetes and Docker .
• Hands-on experience with tRPC , PostgreSQL , and modern frontend tooling.
• Proven track record designing, scaling, and maintaining complex software architectures for high-growth products.
• Experience operating at scale: synchronising large datasets, handling high volumes of API/LLM calls, and building secure multi-tenant systems.
• Experience mentoring junior developers or leading a small development team.
• Ability to own the product roadmap, drive technical decisions aligned with product goals, and collaborate with product managers and designers.
• Excellent written and verbal communication skills in English.
• Authorised to work in Germany without company visa sponsorship.

Compensation & Benefits
Salary: €70,000 – €90,000 per year (depending on experience).
High degree of autonomy and product ownership from day one.
Work directly with a senior engineering team on a product with real, growing traction in the SME AI space.
Location
This is a hybrid role based in Munich, Germany . Candidates must be based in or willing to relocate to Munich. Visa sponsorship is not available.