Senior Full-Stack AI Engineer

Location: Lisbon; Belgrade Workplace: OnSite Aghanim is an integrated commerce, liveops automation, community engagement, and payments platform for video games.   Mobile games have traditionally depended on app stores for distribution, payments, and player relationships. We believe there is a better way. Aghanim helps game studios build direct relationships with players, sell directly, and build their future on their own terms. Today, more than 100 games worldwide are already building this future with Aghanim.   Our team brings together people across Los Angeles, New York, Seoul, Beijing, London, Lisbon, Belgrade and other locations around the globe, with deep expertise in gaming, fintech and technology. We move quickly, keep communication direct, and focus on getting things done. We believe the best people thrive when they have autonomy, ownership, and a stake in the company's success. [https://app.ashbyhq.com/api/images/user-content/4f457f07-466b-477b-b552-fbbabd850111/2de3a7cd-8843-41a9-8bbe-ceb897a42c4a/Logo%20(horizontal).svg] We’re looking for two Senior Full-Stack AI Engineers to help us develop Newton, Aghanim’s AI product for partners. Newton is already a working product with an established architecture. Your role is to ship features across the backend and frontend, build new agent capabilities, and own the engineering quality of what you deliver. You’ll work closely with product and design to understand what partners need, translate specifications into reliable software, and challenge requirements when something does not add up. Product direction, design, and infrastructure have dedicated owners, so your focus is engineering execution. KEY RESPONSIBILITIES - Deliver features from specifications and designs to production, covering database schemas, APIs, agent capabilities, React interfaces, tests, and deployment. - Build agent tools and skills, integrate with Aghanim’s Dashboard API, and access analytical data through the data gateway. - Version and test prompts, tools, and skills; evaluate answer quality and manage runtime costs and failure handling. - Design modules and API contracts within the existing architecture, proposing improvements when implementation reveals gaps. Tech stack: TypeScript, React, Cloudflare Workers, Durable Objects, AI Gateway, Cloudflare OS agent core, Postgres (Supabase), Cube.js, BigQuery, Vitest. Newton currently runs on Claude, with configurable model selection. REQUIRED QUALIFICATIONS - Strong production experience across both backend and frontend with TypeScript, React, SQL, Postgres, and API design. - A track record of shipping features quickly while maintaining code quality and reliability. - Hands-on experience with production LLM applications, including agents, tool calling, structured outputs, and quality evaluation. - Ability to understand product needs, challenge unclear requirements, and work independently within an established architecture. - Daily use of AI coding agents, with a clear approach to reviewing, testing, and validating their output. Important: Commercial experience is required; personal projects alone are not sufficient. PREFERRED QUALIFICATIONS - Experience with Cloudflare Workers, Durable Objects, or AI Gateway. - Familiarity with Supabase, Cube.js, or BigQuery. - Experience building products for games, monetization, or B2B dashboards. WHY JOIN US - World-class team – work alongside experienced professionals from around the globe who have built products used by millions of players - High growth, high impact – be part of a fast-growing company where ideas turn into products and reach customers in days, not months - Autonomy and ownership – we trust people to make decisions, take initiative, and drive results - Modern tools and technology – use AI, automation, and modern tools as part of your everyday work - Equity – participate in the company's growth and long-term success