Founding Software Engineer

About the Role

This is a rare opportunity to join a fast-growing, Y Combinator-backed AI SaaS startup in the motion design space as its first engineering hire . The company is building an AI-powered platform that dramatically accelerates animation creation — reducing what once took hours into minutes — and has already seen remarkable early traction since launching earlier this year.

As a Founding Software Engineer, you'll work shoulder-to-shoulder with the founders to shape the technical foundation of the product, own features end-to-end, and help architect a system built to scale to millions of users.

What You'll Do

• Partner directly with the founding team to deliver user-centric product solutions from concept to production.

• Own end-to-end development of full-stack features with a focus on scalable architecture design.

• Build and optimize agentic LLM systems incorporating tool-calling, multi-step reasoning, and MCP protocols.

• Design comprehensive LLM evaluation frameworks including automated benchmarks, human-in-the-loop validation, and A/B testing.

• Optimize LLM inference performance, cost efficiency, and latency across multiple model architectures.

• Develop a high-performance motion graphics engine.

• Drive architectural decisions that support scalable growth to millions of users.

What We're Looking For

Required

• 2+ years of software engineering experience with strong CS fundamentals.

• Proficiency in TypeScript (dealbreaker requirement).

• Hands-on experience building or integrating large language models (LLMs), including tool-calling, multi-step reasoning, and MCP protocols.

• Experience designing and implementing LLM evaluation frameworks (automated benchmarks, human-in-the-loop validation, A/B testing).

• Demonstrated ability to deliver end-to-end full-stack features with scalable architecture.

• Proficiency optimizing LLM inference performance, cost efficiency, and latency across multiple model architectures.

• Experience with the full tech stack: TypeScript, React.js, Next.js, PostgreSQL, GCP, AWS .

• Prior startup or early-stage company experience with a strong ownership mindset.

• Willingness to work on-site in Berlin, Germany .

Nice to Have

• Background in animation, motion graphics, or creative tooling.

• High slope / fast-learning profile with a track record of rapid growth.

Compensation & Benefits

• Salary: €80,000 – €160,000 per year, depending on experience.

• Early-stage equity opportunity as the founding engineering hire.

• Visa sponsorship: Not available — candidates must already have the right to work in Germany.

Location

• Berlin, Germany — fully on-site role.

• Remote work is not available for this position.