Founding Software Engineer

We’re building the world’s first AI motion designer and this is our founding engineering hire. You’ll work closely with the founders to shape the technical foundation, own end-to-end development, and help scale a product designed to empower millions of users with fast, high-quality animations.

What youll do

• Partner with the founders to deliver user-centric product solutions from concept to production.
• Own end-to-end development of full-stack features with scalable architecture design.
• Build and optimize agentic LLM systems incorporating tool-calling, multi-step reasoning, and MCP protocols.
• Design comprehensive LLM evaluation frameworks with 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 Hera (YC S25) is looking for

• Strong CS fundamentals.
• Hands-on experience building or integrating large language models (LLMs), tool-calling, multi-step reasoning and MCP protocols.
• Experience designing and implementing LLM evaluation frameworks with automated benchmarks, human-in-the-loop validation, and A/B testing.
• Demonstrated ability to deliver end-to-end full-stack features with scalable architecture.
• Startup/early-stage company experience with an ownership mindset.
• Proficiency with the full tech stack (TypeScript, React.js, Next.js, PostgreSQL, GCP, AWS).
• Proficiency in optimizing LLM inference performance, cost efficiency, and latency across multiple model architectures.
• Willingness to work on-site in Berlin, Germany (office-based).