Founding Engineer

Kantrip turns a game idea into a game on the App Store and Google Play. A creator describes a game, our agent builds it, and the creator shapes it in our editor until it ships.

You build that whole system: the agent that writes the games, the editor creators work in, and the services underneath. We are hiring two founding engineers. You work directly with the founder and our founding engineers. You own whole systems end to end, not tickets.

• Build the agent that plans, builds and fixes games, and the evals that prove it got better.
• Build the editor: the chat, the live preview and the tools creators use to shape a game.
• Shape the creator experience, from the first idea to a live game.
• Build the backend and infrastructure that run builds, store games and serve the editor.
• Build the pipelines that turn a game into signed releases on both stores.
• Find what breaks, trace the root cause, and fix the system, not the symptom.

• Startup experience. You shipped at an early-stage company, or you founded one.
• You shipped production software end to end: frontend, backend and infrastructure. We work in TypeScript; deep experience in another language is fine.
• Exposure to games. You built a game, an engine, an editor, a games tool or a game backend, or you worked at a games company.
• You care about the product and the user experience, not only the code.
• You use coding agents every day, and you check their output.
• You take an unclear problem, decide what to build, and ship it.
• Based in (or willing to relocate to) London. We work in person, five days a week, from our office in Bloomsbury.

• ML/AI experience: LLM agents or evals in production, research engineering at an AI lab, game-playing agents, or fine-tuning.