Senior Full Stack Engineer (w/m/d)

SelectCode is hiring a Senior Full Stack Engineer to help scale an AI platform that already serves 100k+ users across 250+ companies toward 1M users. You will join a product-focused engineering team building secure, scalable systems and intuitive UX to bring AI to the core of the SME sector.

What you'll do

• Own the most complex architectural problems across the platform, such as multi‑terabyte data synchronization 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 synchronize and index terabytes of client data while enforcing permissions.
• Build infrastructure to process millions of LLM calls per month with high reliability and security.
• Implement scalable, secure code sandbox solutions that can spawn 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 development team.
• Debug production incidents, identify root causes, and implement durable fixes to keep the platform stable.
• Mentor junior colleagues and improve the codebase through constructive, thorough code reviews.
• Continuously improve development processes, code quality standards, and team performance.

What SelectCode is looking for

• 7+ years of professional software engineering experience working with React, TypeScript, PostgreSQL, and the surrounding ecosystem (Docker, CI/CD).
• Proven experience designing, scaling, and maintaining complex software architectures for high‑growth products.
• Hands‑on experience with core stack technologies including tRPC, Kubernetes, Docker, and modern frontend tooling.
• Experience operating at scale: synchronizing large datasets, handling high volumes of LLM/API calls, and building secure multi‑tenant systems.
• Strong sense of product ownership with attention to user experience and long‑term product success.
• A passion for mentoring engineers and actively shaping engineering standards and processes.
• Comfortable learning quickly and working in a fast‑paced, high‑growth environment.