Lead/Senior AI FullStack Software Engineer

About the client:

Our customer is the European online car market, with over 30 million monthly users and a presence in 18 countries. As a Lead FullStack Engineer, you will play a pivotal role in shaping the future of online car markets and enhancing the user experience for millions of car buyers and sellers.

Responsibilities:

• Continue the evolution and scaling of our freshly released, native ChatGPT apps and custom MCP integrations.
• Develop and maintain high-traffic, public-facing interfaces hosted on AWS modern cloud infrastructure.
• Work heavily with AI agents (Claude Code, ChatGPT/Codex) to maintain and extend a codebase 
• Operate with full team autonomy, collaborating closely with the Engineering Manager in a "co-author" environment.
• Follow the "you-build-it-you-own-it" philosophy, taking full responsibility for the SDLC and production readiness.
• Explore and implement emerging AI frameworks and technologies to keep the product at the forefront of the GenAI market.

Requirements:

• 7+ years of experience developing reliable, highly available, and scalable software systems.
• Strong experience working with AI agents (Claude Code, ChatGPT/Codex) to maintain and extend a codebase
• Strong proficiency with backend development using Node.js / Java/ .Net and TypeScript.
• Deep experience with Model Context Protocols (MCP).
• Proven track record of using AI tooling (ChatGPT, Codex, Claude Code) for rapid operator-driven development.
• Hands-on experience with modern cloud infrastructures, specifically AWS, Terraform, and Docker.
• Strong proficiency with frontend development (HTML, CSS, JavaScript) and component-based SSR frameworks like Next.js or React.
• Experience with SQL and NoSQL datastores, as well as developing in service-based API environments.
• Strong understanding of software architecture, design patterns, and clean code principles.
• A modern, energetic mindset with critical thinking and systemic vision skills, the ability to work independently and take high-level ownership.
• Experience with formal CI/CD pipelines and monitoring services.
• Upper-intermediate English level.