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Kantrip
Careers · London

A game studio in everyone's hands.

Making a good mobile game still takes a studio, years, and an engine built for specialists. We're tearing that open. We are building an AI-native game engine, and the agents that drive it, so anyone can build native, high-performance games that ship to the stores and make money. Come build it with us.

Why we exist

Mobile games are a $150bn+ industry, and almost none of the tooling is built for the people who could be making them. The engines are heavy, the knowledge is specialist, the path from idea to a polished, shippable game is brutal. So most great game ideas never get made.

We think that's about to change. AI can do the heavy lifting of building a game if it has the right engine underneath. So we're building that engine in TypeScript, the language AI writes best, and the agent pipeline on top of it that takes a game from idea to the App Store. People bring the taste and the machine brings the speed.

It's a hard problem and nobody has solved it yet. That is why we picked it.

How we work

Ownership
Own whole systems, end to end. Small team, enormous surface area. You'll design your systems, build them, ship them, and tune them live.
Pace
Build with AI, move at its speed. We're AI-native, we ship quickly, and we expect everyone to push what agents can do.
In person
In the room, in Bloomsbury. We build side by side, five days a week, from our office in Bloomsbury, central London.
Honest
Honest about the stage. We're early. There's execution risk and founder-level intensity for the first stretch. We say so up front so nobody joins expecting otherwise.

Open roles

4 roles · London · always interviewing

We hire whenever we meet exceptional people. Seats stay listed after they are filled, so apply even when the timing looks wrong.

The role

We're building an agent system that turns a game spec into a shipped game. We have a working system but we know it can always be better. You own that system and where it goes next, we can't just use off the shelf system, games need specific loops, context and the economics matter.

Model releases lift everyone equally. You'll be building the system that turns those models into games people want to play. You work with the founder and our engine and platform teams to build agents that bridge the gap between prompt and playable.

What you'll do
  • Design, build and operate the pipeline that takes a game from spec to shipped build: planning, code generation, review and release.
  • Build evaluation and regression tooling that measures output quality and catches failures automatically.
  • Build the routing layer that selects a model for each pipeline step based on quality, latency and cost.
  • Replace third-party agent infrastructure with our own runtime where that improves quality, control or cost.
  • Build our retrieval and context systems, and lead fine-tuning of models on the data the platform generates.
What we're looking for
  • You follow the field closely and test new models and techniques as they're released.
  • You've built LLM systems in production: multi-step pipelines, tool-using agents, or eval infrastructure.
  • Strong systems engineering background. We work in TypeScript; deep experience in another language is fine.
  • You've designed and run evals: test sets, benchmarks, regression tracking.
  • You've managed inference cost alongside quality and latency in a production system.
  • Based in (or willing to relocate to) London. We work in person, five days a week, from our office in Bloomsbury.
Bonus
  • Model routing or gateway infrastructure.
  • Fine-tuning, post-training, or retrieval systems.
  • A background in games.
Think this is you?Send an emailor email careers@kantrip.dev

Share this role: kantrip.dev/careers/founding-ai-engineer

How we hire

We keep it short, we pay for your time, and you know the bar at every stage.

01 · Intro call
30 minutes. What we are building, what you have built, and whether to keep going. Either side can stop here.
02 · Technical walkthrough
60 minutes. You walk us through the best thing you've built: your code, your screen.
03 · Paid exercise
£250 flat, 2 to 4 hours, done in your own time within a week. AI tools allowed and expected: that's how we build. The pass criteria are stated upfront. Followed by a 30-minute debrief on how you approached it.
04 · Coffee
In person in London, plus references. Then we decide.

End to end in about two weeks.

Don't see your role?

If you're exceptional and you want to help put game-making in everyone's hands, we still want to hear from you.

Get in touch

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