Founding Software Engineer

Clera•San Francisco, CA

1d•€80,000 - €160,000•Onsite

About The Position

A Y Combinator-backed AI creative tools startup is hiring its founding software engineer. You'll work directly with the founding team to shape the technical foundation of an AI-powered motion design platform — turning what once took hours into minutes for professionals and video teams worldwide. This is a high-ownership, zero-to-one role at a company with strong early traction and rapid revenue growth.

Requirements

2+ years of software engineering experience with strong CS fundamentals.
Proficiency in TypeScript (dealbreaker); hands-on experience with React.js, Next.js, PostgreSQL, GCP, and/or AWS.
Proven experience building or integrating LLMs — tool-calling, multi-step reasoning, and MCP protocols.
Experience designing 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 at scale.
Background in startups or early-stage environments with a strong ownership mindset.
Ability to optimize LLM inference for performance, cost, and latency across multiple model architectures.

Nice To Haves

Experience in AI creative tools, motion graphics, or animation-adjacent products.
High learning velocity and ability to ramp quickly in a fast-moving environment.

Responsibilities

Partner with the founders to deliver user-centric product features from concept to production.
Own end-to-end full-stack development with a focus on scalable architecture.
Build and optimize agentic LLM systems, including tool-calling, multi-step reasoning, and MCP protocols.
Design and implement comprehensive LLM evaluation frameworks — 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 to support growth to millions of users.