Senior Full-Stack AI Engineer — Rails & AI Infra, Remote

United States Digital Space LLC; United States; Remote; USD 130,000 - 140,000; Full time

Benefits offered by this job

PTO 35 days

Remote‑only team

Equity grants

Health & wellbeing

Job summary

Circle is hiring a strong full‑stack engineer to build AI solutions using a Ruby on Rails backend and a React frontend. You will lead end‑to‑end AI projects, run experiments, and integrate AI infrastructure for scalable inference.

You should have hands‑on experience with AI features in production and a strong mindset for rapid experimentation, A/B testing, and learning. The role is remote and globally distributed with a focus on speed and quality.

Qualifications

• 6+ years experience as a full-stack engineer on high-traffic production applications.
• Proficiency in Ruby on Rails, MySQL / PostgreSQL, ReactJS.
• Hands-on experience building AI features in production.
• Strong experimentation mindset with ability to design/run A/B tests.
• English proficiency at CEFR Level C2 / ILR Level 5.

Responsibilities

• Ship full‑stack AI projects end‑to‑end using Ruby on Rails backend and React frontend.
• Design and run experiments (A/B tests, AI evaluations) to validate features and guide iteration.
• Build and integrate AI infrastructure components for production‑level inference and reliability.
• Improve processes and tools to scale AI features into production solutions.
• Stay up‑to‑date with AI research, techniques, and tools, and apply them to projects.
• Collaborate with Circle’s leaders and designers throughout feature design.
• Maintain high standards of code quality and user experience while iterating quickly.

Skills

Ruby on Rails

MySQL

PostgreSQL

ReactJS

A/B testing

AI features in production

Job description

Circle is hiring a strong full‑stack engineer to build AI solutions using a Ruby on Rails backend and a React frontend. You will lead end‑to‑end AI projects, run experiments, and integrate AI infrastructure for scalable inference.

You should have hands‑on experience with AI features in production and a strong mindset for rapid experimentation, A/B testing, and learning. The role is remote and globally distributed with a focus on speed and quality.