Senior Full-Stack AI Core Engineer (Rails/React)

Circle; Portugal; Presencial; EUR 112 000 - 121 000; Tempo integral

Vantagens oferecidas por esta oferta de emprego

U.S.-benchmarked compensation globally

Equity with refresh grants

35 days paid time off

Resumo da oferta

Circle is a fully remote company with a global team and a commitment to innovation in AI for community platform features. We seek a strong full-stack engineer proficient in Rails and React to drive end-to-end AI projects, including AI agents, Retrieval-Augmented Generation, AI evaluations, and LLM inference infrastructure.

The role emphasizes hands-on AI development, rapid experimentation, and collaboration with product and design leaders.

Qualificações

• 6+ years experience working as a full-stack engineer on high-traffic production applications.
• Strong proficiency in Ruby on Rails, MySQL / PostgreSQL, ReactJS.
• Hands‑on experience building AI features in production (RAG, AI agents, or LLM-powered tools).
• Strong experimentation mindset with A/B testing and rapid iteration.
• Desire for speed of iteration, autonomy, accountability, and collaboration in a dynamic team.
• Fluent in English (CEFR C2 / ILR 5).

Responsabilidades

• Ship full-stack AI projects end-to-end on a product built with Rails and React.
• Design and run experiments (A/B tests, AI evaluations) to validate features and guide iteration.
• Build and integrate AI infrastructure components and optimize for production-level inference.
• Improve processes and tools to scale AI features into production-ready solutions.
• Stay up-to-date with cutting-edge AI research and tools.
• Collaborate with Circle's leaders and designers throughout feature design.
• Maintain high code quality and strong user experience while iterating quickly.

Conhecimentos

Full-stack engineering

Ruby on Rails

ReactJS

MySQL / PostgreSQL

AI features in production

Experimentation (A/B tests)

English (CEFR C2)

Descrição da oferta de emprego

Circle is a fully remote company with a global team and a commitment to innovation in AI for community platform features. We seek a strong full-stack engineer proficient in Rails and React to drive end-to-end AI projects, including AI agents, Retrieval-Augmented Generation, AI evaluations, and LLM inference infrastructure.

The role emphasizes hands-on AI development, rapid experimentation, and collaboration with product and design leaders.