Staff Product Engineer (AI Focus)

Gizmo is an AI startup on a mission to make learning so easy that anyone can learn anything. We're building a platform that uses gamification and social mechanics to make learning fun.

With over 1.7 million monthly active users and $5M in annual recurring revenue, we’re already one of the fastest-growing startups in the UK. Backed by leading investors, we recently raised $22M in Series A funding to accelerate our vision of helping 1 billion people learn.

The Role

We’re hiring an experienced/staff-level Product Engineer (AI-focused) to build and scale the core intelligence behind Gizmo.

Reporting to the CEO and Co-Founder, you’ll work across our TypeScript codebase to ship AI-powered features used daily by thousands of students, including study material generation, quizzes, automated marking and content ingestion.

This is not an ML research role. It is a hands-on product engineering position focused on designing and improving production AI systems with real user impact.

If you want to build AI that sits at the heart of a product and see your work make a tangible difference at scale, this role offers genuine impact.

What You Will Be Doing

Building AI-Powered Product Features

You will operate as a full product engineer, owning AI features end to end:

• Design and ship AI-driven user-facing features in our TypeScript stack
• Take ownership of AI features from idea through to production and iteration
• Collaborate closely with design and product to solve real learning problems with end to end AI solutions
• Write clean, maintainable, production-ready code
• Contribute to architectural decisions across backend and AI systems
• Improve the user experience around AI outputs, including feedback loops and refinement flows

Owning and Improving Production AI Systems

You will take responsibility for AI systems that are already live and used daily.

These include:

• Study material content generation
• Quiz question generation
• Automated marking and feedback
• Structured content ingestion pipelines

You will:

• Optimise production AI pipelines
• Design and iterate on prompts, including agentic prompt engineering and multi-step workflows
• Build structured model pipelines rather than simple single-call integrations
• Integrate model improvements directly into our TypeScript backend
• Create novel AI-powered systems to solve new product challenges
• Prototype and productionise new model-driven capabilities

Designing Evaluation and Quality Frameworks

You will:

• Define what great looks like across different AI use cases
• Design internal evaluation frameworks
• Develop clear metrics for quality, correctness and usefulness
• Evaluate multi-step and agentic workflows for robustness
• Run structured experiments to drive systematic improvement
• Build internal tooling to support iteration and experimentation

Ensuring Reliability at Scale

You will:

• Monitor model behaviour and system health
• Handle API rate limits and third-party outages
• Improve resilience, retries and fallback logic
• Design robust model-calling infrastructure
• Ensure AI features remain stable and performant under scale

Requirements:
• 8+ years of software engineering experience
• Strong expertise in TypeScript is preferred; however, we would also consider candidates with strong JavaScript experience
• Degree in Machine Learning, Artificial Intelligence, or a related quantitative discipline; alternatively, demonstrable hands-on experience evaluating AI models and prompts in a production environment
• Experience building and maintaining production systems
• Experience shipping user-facing product features
• Experience designing structured or agentic prompt workflows
• Ability to define and implement evaluation metrics for AI-driven features
• Clear communicator who can collaborate with technical and non-technical stakeholders
• Strong product instincts and a focus on impact

Nice to Have

• Previous start-up or founder experience
• Experience building internal tooling for experimentation and evaluation

Benefits:
• Highly competitive salary
• You'll own a piece of what you're building - equity included
• Hybrid and flexible working model with 4 days in our Shoreditch, London office
• Private health insurance
• Enhanced parental leave
• The opportunity to become one of the earliest employees in one of the UK’s fastest-growing startups