Job description

Senior Software Engineer – Gandalf

Lakera is on a mission to secure the era of intelligent software. At the heart of this mission is Gandalf. The world’s most popular AI security game, played by millions globally. Gandalf isn’t just a viral success. It's become a proving ground for adversarial testing of LLMs and a cornerstone of how the world learns about AI safety.

We're now looking for a Product-Focused Software Engineer to take Gandalf to the next level. This is a rare opportunity to own a beloved product with massive reach and shape its future. You’ll work at the intersection of gaming, UX, and cutting-edge AI building immersive, secure, and delightful experiences that people actually love.

What you’ll do

Own the end-to-end product development of Gandalf. From gameplay mechanics, frontend and backend scalability.
Partner with researchers and product leads to prototype, test, and launch new game modes and features.
Shape and implement the user experience: animations, transitions, performance, and polish the details that turn a toy into magic.
Make Gandalf more social, more replayable, and more extensible. Think real-time competition, player profiles, in-game progress, and more.
Help define the roadmap, not just execute it — your product sense matters here.
Drive massive product impact: Gandalf isn't just about building great games, it's a core surface through which we test, validate, and improve our models. The work you do here directly shapes model performance, product quality, and ultimately business outcomes.

You might be a fit if you

Have strong frontend skills (React, TypeScript) and solid backend engineering chops (e.g., Python, Next.js, Firebase, or similar).
Thrive in zero-to-one product environments and want real ownership.
Are passionate about games, user experience, and AI and love building things people can’t stop using.
Think like a product builder: you care about outcomes, not just code quality.
Can move fast independently but collaborate deeply across teams.

Bonus points for

Experience working on games, interactive web experiences, or viral consumer products.
Working knowledge of LLMs or prompt injection (you’ll learn fast if not).
A track record of building side projects or launching products end-to-end.

Why this role?

Massive visibility: Gandalf is already a viral hit. You'll shape what millions interact with next.
Fast-moving, product-first team: No bureaucracy. No silos. Just you and a small team building the future.
Deep mission: At its core, Gandalf helps the world understand and secure AI. It’s fun but it matters.
Foundational seat: This is not a maintenance role. You’re here to invent.

Apply now to build the most loved and most important game in AI.