Founding AI Engineer

About

• We're building the future of storytelling and video editing.
• We're a small team that moves fast and builds things we're proud of.
• We care obsessively about taste in design, in code, in product.
• We're backed by YC and Tier-1 global funds.

Engineering

Video is the most powerful way humans tell stories. It always has been. But creating it today is still painfully hard. Fragmented tools, steep learning curves, and workflows that get in the way of the actual creative work. We're building Cardboard to change that.

As a founding AI engineer in our team, you'll own the agent harness end to end. That means figuring out why a model behaves differently when a prompt shifts by a sentence, digging through conversation histories for patterns, and building your own evals and datasets to actually know if things are improving.

We want someone who has shipped real AI systems in production, not demos, but things that held up. Someone who understands LLMs deeply enough to have opinions about them. If you've worked seriously with memory, that's a big plus.

You will

• Own the agent harness, from architecture to production.
• Understand model behavior at a deep level: prompts, versions, context, and why it all matters.
• Write and maintain your own evals, benchmarks, and datasets.
• Dig through conversation histories and turn what you find into product improvements.
• Solve these problems.
• Make something people love.