About Us
Circle is building the world’s leading all-in-one platform for online communities. We make it possible for creators, coaches, educators, and businesses to bring together their audience with engaging discussions, live streams, events, chat, courses, and payments — all in one place, all under their own brand.
We’re proud to be a fully remote company of around 200 team members from 30+ countries. We collaborate across time zones, are highly async, and maintain high standards.
About the role
The Applied AI team at Circle is at the forefront of leveraging AI to drive innovation for our customers through transformative applications of large language models (LLMs). We're looking for a strong full-stack engineer proficient in web frameworks, backend development, and infrastructure to spearhead the development of full-stack AI solutions.
You will work on exciting projects such as AI agents, Retrieval-Augmented Generation (RAG), AI evaluations and observability, and building infrastructure for LLM inference. We are looking for an individual with an experimentation mindset who is excited about rapidly testing ideas and iterating on production use cases.
What you'll be doing
- Ship full-stack AI projects end-to-end on a product built in Ruby on Rails backend and React frontend.
- Design and run experiments (including A/B tests and AI evaluations) to validate AI features and measure impact.
- Build and integrate components for AI infrastructure, optimizing for performance and reliability for production-level inferencing.
- Improve processes and systems to scale AI features into production-ready solutions.
- Stay up-to-date with cutting-edge AI research, techniques, and tools.
- Foster a bias for action by prioritizing speed of iteration and learning while maintaining high code quality.
What you'll need to be successful
- 6+ years of experience working as a full-stack engineer on high-traffic production applications.
- Strong proficiency in Ruby on Rails, MySQL / PostgreSQL, and ReactJS.
- Hands-on experience building AI features in production, such as RAG systems, AI agents, or LLM-powered tools.
- Strong experimentation mindset with experience designing and running A/B tests.
- Ability to work in a fast-paced, autonomous environment with a high level of accountability.
- Proficiency in English at a CEFR Level C2 / ILR Level 5.