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.