Full Stack Developer - AI Products (React & Next.js)

About the Company

This opportunity is with a fast-moving consumer technology business building a portfolio of AI-powered consumer products aimed at a global audience. The business is well funded, has a strong runway, and is led by a founder with a serious track record of building and scaling consumer internet businesses to significant exits.

The portfolio spans consumer AI, prediction markets and AI-generated content, with live products already in market and global press attention. The core technology has been built and proven, the team is in place, and the focus now is taking these products to the world.

The team is small, senior and AI-native. Full architecture rebuilds are measured in days, not quarters, and engineers are trusted with real ownership from day one. This is an environment for someone who wants to build complete, polished experiences, ship continuously, and see their work in the hands of real users quickly.

Job Overview

We are looking for a senior full-stack engineer to help build the next wave of this company's AI products. The core architecture, data pipelines and engines are already built and proven. Your job is to take new product verticals from an existing engine through to a live, playable, beautifully finished product, owning the full slice from the data your product consumes to the polished, mobile-first world players actually use. More than ten further products are planned for a global market, so this is a build-heavy role with a long runway.

This is a genuine full-stack role. Ideally you are strong across both a Python and FastAPI back end and a Next.js and React front end. Front-end and product craft is where the role leans most, since the experience layer is what makes each product succeed, but you will also work across the back end, building on top of the existing services and engines rather than architecting them from scratch.

The role works closely with, and reports to, the technical founder, who owns the underlying engines and architecture. It will suit a senior engineer who enjoys full ownership across the stack, has real front-end and product strength, and is genuinely interested in markets, odds and probability. In return you get a defined role on an exciting product, real autonomy, and the chance to help take a category-first business to a global audience at pace.

Duties and Responsibilities

Building New Product Verticals End to End

• Take each new vertical from an existing engine and data pipeline through to a live, playable product.
• Own the full slice, from the data each product consumes to the finished, mobile-first world players use.
• Ship complete, polished products to production continuously as new verticals are added.

Front-End and Game-Grade Interfaces

• Build mobile-first front-end worlds in Next.js 15 (App Router), React, TypeScript and Tailwind CSS v4.
• Create rich, animated interfaces where motion comes from real, moving data, using tools such as MapLibre GL, particle layers and live WebSocket feeds.
• Work with TanStack Query and zod-validated API contracts, keeping business surfaces clean and easy to read.

Back-End and Data Integration

• Work across the existing Python 3.12 and FastAPI back end, building on top of established services and engines.
• Extend APIs, schemas and data flows (SQLAlchemy, asyncpg, Alembic, PostgreSQL) to support new products.
• Handle financial values with exact-decimal precision and respect the existing correctness culture.

Correctness, AI-Assisted Delivery and Ways of Working

• Uphold a correctness culture where every surface reports honestly when a data source is unavailable, rather than masking the failure.
• Direct, review and ship AI-assisted work to senior-engineer quality, using AI coding tools as a core part of how you build.
• Work in small pull requests with fast review loops and deploy-on-merge, on Google Cloud with GitHub Actions CI/CD.

Minimum Requirements

• Senior full-stack engineering depth, ideally strong across both a Python and FastAPI back end and a Next.js, React and TypeScript front end.
• Particular strength in front-end development and building high-quality, mobile-first user interfaces.
• Comfortable working across the back end and building on top of existing services and engines, rather than needing to architect them from scratch.
• Exposure to PostgreSQL and modern ORM and data tooling such as SQLAlchemy and Alembic.
• Heavy, skilled use of AI coding tools to compress build time without compromising quality.
• Speed as a habit, including small pull requests, fast review loops and comfort with deploy-on-merge.
• A genuine interest in markets, odds and probability.
• Strong product sensibility, with clear opinions on what makes a mobile interface work and the restraint to keep business surfaces clean.

Nice to Have

• Map, canvas or WebGL rendering experience, such as MapLibre, particle layers or GPU heatmaps, which is a strong plus given the map-based worlds.
• A games or gaming background, including experience building game loops, progression systems or game-quality user interfaces.
• Experience with real-time data systems, including WebSockets at scale and streaming ingestion.
• Deeper back-end or data-engineering strength, including building services, engines or pipelines from scratch.
• LLM API experience beyond chat, including tool use, agents and structured output.
• Production experience on Google Cloud or an equivalent platform.
• A tertiary qualification in Computer Science, Software Engineering, Mathematics or a related field.

Personal Attributes

• Comfortable with high autonomy and full end-to-end ownership across the stack.
• Biased towards shipping, in small, frequent increments.
• Collaborative and receptive to feedback, with a strong work ethic.
• Rigorous about correctness, quality and honest failure states.
• Genuinely curious about markets, odds and probability.
• Product-minded, with a good sense of what makes a mobile experience enjoyable and where detail becomes noise.

How to Apply?

If you are a senior full-stack engineer with real front-end strength, enjoy owning complete products, and like shipping fast with modern AI tooling, we would like to hear from you. With more than ten further AI products planned for a global market, this is a rare chance to build at pace and see your work in the hands of real users.

Email your CV to charne@skillzpage.com

(If you don’t hear from us within 2 weeks, please consider your application unsuccessful.)