Lead AI Engineer, Game Generation in London

Lead AI Engineer, Game Generation

TechTree acts as the recruitment agency for this opportunity.

Location: London, United Kingdom
Working arrangement: On-site in London from October 2026; remote start permitted until then
Employment: Full-time
Level: Mid-Senior Level

Advertised compensation: $120k–$150k, plus equity. The client also states that compensation is open for the right candidate.

About Nanogram

Nanogram is a TikTok-style mobile feed where every item is a short, AI-generated browser game - anyone can make one from a prompt.

The role

The game-generation pipeline is the product, which makes this the most important hire the client is making right now. Every game in the feed comes out of it: a creator's prompt intent extraction template matching model routing asset retrieval generation validation and repair runtime play telemetry back into the loop. It's built around a fixed library of ~20 proven core mechanics with hard-constraint specs (every line pass/fail checkable), and a quality score fed by real play data - completion, replay, share/remix.

You'll own that system end to end and be judged on two numbers moving at once: playability pass rate up, cost per generation down, at volume.

This is not a prompt-engineering role, and not a research role where someone else ships your work. It's also not "LLM app" building - the output here has to compile, run and be fun, millions of times, at a cost that works. You'll work with core engineering in Sofia and with game design; there's a team on the pipeline today and you become its technical owner, and lead it if you can. Comp is open - the client will pay top of market for the right person.

What you'll do

• Own the full generation pipeline: intent extraction, template matching, model routing, asset retrieval, generation, validation and repair, runtime, and play telemetry feeding back into the loop.

• Move playability pass rate up and cost per generation down, at volume.

• Run benchmark suites, LLM-as-judge and playability pass/fail checks, and show output quality improving over time.

• Own the economics: tiered model routing, RAG/templates, caching, small-model distillation.

• Stay hands-on in the runtime: browser/JS games, procedural content, asset/image generation.

What you bring

• Have shipped text-to-game or AI game-creation tech (Rosebud, Bitmagic, Astrocade, Websim, Roblox Cube/Assistant, Hidden Door calibre) - or the next-closest thing: a prompt-to-running-app agent at scale (Replit Agent, Lovable, Bolt, v0 calibre).

• Own the full loop: generation validation repair eval, with benchmark suites, LLM-as-judge and playability pass/fail checks.

• Know the economics cold: tiered model routing, RAG/templates, caching, small-model distillation - have cut cost per generation 10x somewhere.

• Strong enough engineer to live in the runtime too: Three.js, Phaser, Babylon, voxel engines, procedural content, asset/image generation.

Nice to have

• Research credentials in generative game tech (DeepMind Genie/SIMA, Microsoft Muse, LLM-driven PCG papers).

• Has led a team of 2-3.

• Fine-tuned or distilled open models in production.

• Image or 3D asset generation experience.

• Game-engine background (Unity/Godot).

• Startup or founding-team experience.

Hiring process

• CV

• Technical Interview (1 hour)

• System design interview (90 min)

• Paid take-home (1-2 hours to complete)

Logistics

• Location: London, in person. Long-term this isn't flexible - the client requires the team to work together in person.

• Remote until October 2026: you can start immediately from wherever you are and join the office in October. Relocation to London by October is a condition of the offer.

• Full-time.

• Compensation: base + equity, open - the client will pay top of market for the right person.

Benefits

• 6% pension
• Private health and dental cover
• Gym allowance
• Commuting season-ticket loan
• Visa sponsorship