Founding Engineer | Full-Stack Developer

• Architect, build, and maintain core product features across our full-stack (frontend, backend, and infrastructure).
• Lead development of AI-powered simulation logic, scoring workflows, and conversation pipelines.
• Take ideas from concept * prototype * production with high velocity and strong product intuition.
• Collaborate closely with founders on product decisions, technical strategy, and customer feedback loops.
• Establish engineering best practices around testing, code quality, security, and documentation.
• Build internal tools to speed up content creation, scenario building, and customer onboarding.
• Optimize performance, reliability, and scalability as the platform grows in usage and complexity.
• Help recruit, mentor, and shape Sleak AI’s future engineering team.

• 2-5+ years of experience as a full-stack engineer, ideally in early-stage startups or fast-paced product environments.
• Strong expertise in modern frontend frameworks (preferably Next.js), backend technologies (Node.js, Python), and Databases (PostgreSQL).
• A product-obsessed mindset: you care about user experience, not just clean code.
• Comfort with ambiguity and a builder mentality - proactive, ownership-driven, and resourceful.
• Experience designing and working with APIs (preferably REST) and cloud infrastructure (preferably Azure).
• Excellent communication skills and the ability to work directly with founders and customers.
• Hands-on experience using AI-powered coding tools (e.g., Cursor, Claude Code) to maximize productivity - while maintaining high engineering standards.
• Availability to work a minimum of 3 days per week from our Munich office.

Optional:

• Familiarity with vector databases, LLM APIs, prompt engineering, or conversational AI systems.
• Ability to design scalable architectures and make thoughtful trade-offs between speed and robustness.

• Competitive compensation package including equity - join early, grow with us.
• Full ownership of major product components and the freedom to shape their long-term direction.
• Work closely with founders and contribute directly to product, vision, and company strategy.
• Remote-friendly setup with flexible working hours.
• Annual off-sites, team trips, and a culture that values autonomy, speed, and craftsmanship.
• Access to cutting-edge AI tools, models, and workflows - experiment and innovate daily.
• Wellpass Membership

If you’re excited to build the future of AI-powered sales training and want to join a fast-moving early team with massive ownership, we’d love to hear from you!

Sleak GmbH Munich, Bavaria, 80331

Sleak AI is building the future of sales training. We help companies train their teams through realistic, AI-powered simulations that feel like speaking to real customers. Our platform pushes the limits of real-time conversational AI - demanding smart system design, beautiful and engaging interfaces, and the kind of people who love making all of this come to life.

As one of our first engineering hires, you will play a defining role in shaping the product, the architecture, and the culture of the company. You’ll work directly with the founders, own critical parts of our stack, and help bring a category-defining product to life.

If you’re excited by ownership, love shipping beautiful software fast, and want to build something truly impactful from day one - this role is for you.